Dissonance

CHAPTER THIRTY-SEVEN

I DREW BACK. “Raining? In your dream. In your kissing dream.”

“Too creepy?”

Not creepy. Potentially disastrous, but not creepy. I forced myself to breathe, kissed him again like his words hadn’t upended everything between us. “Tell me about these dreams.”

“We’re going there already? You seemed like such a nice girl.”

“Appearances can be deceiving.”

“They’re not X-rated, if that’s what you’re asking. I’m not a perv.”

“Dreams. Raining. Talk.”

“It’s jumpy. Like bad reception on TV,” he said. He leaned against the bleachers, gathering me in the circle of his arms, running his fingers through my hair and coaxing out the knots. “But it’s you, and it’s raining, and you’re just . . . there. Like I’ve been waiting for you, even if I didn’t know it. And suddenly you’re there, and we’re kissing, and when I wake up, I swear I can still taste you. But they were only dreams. This is better.”

“Because of the rain?”

“Because it’s real.”

He tipped my face up to his and kissed me again, gentle and persuasive, and for a moment longer, I savored him. But when we came up for air, I pulled back, needing to see the truth.

“And it’s always raining?”

“Not always,” he admitted. “The other day, in the library? I was daydreaming. And you were there, but Powell interrupted us. That’s when I decided I was done with dreaming.”

The rain, at least, was a coincidence. Nothing else was. His dreams—and his weird fugue state—weren’t dreams. He was tuning in to his Echoes. His SRT was stronger and more severe than anything I’d heard of.

I drew out an old English assignment from my coat pocket, trying to calm myself.

“What’s the deal with those things?” he asked as I began folding.

“It’s origami.”

“I know that,” he said. “Why do you do it?”

I looked at the paper, seeing the beginnings of a star through his eyes. “Habit. Some people crack their knuckles or twirl their hair. You like to tap your pencil when you’re thinking,” I pointed out.

“And you fold origami?”

“My grandfather taught me. He used to say that each fold was a choice. That I could make whatever I wanted, if I chose carefully.” Make a choice and make a world.

“Can I see it?”

I finished quickly, my fingers unsteady, and dropped it into his outstretched hand. It sat there, white with pale blue lines and smudged pencil marks, an entire reality’s worth of choices in his palm.

“Why do you leave them behind?”

“I didn’t think anyone noticed.” I only did that when I Walked.

“I don’t know when I started noticing them.” He held the star between his thumb and forefinger, spinning it slowly. The gesture was so familiar I wanted to cry.

“Probably the same time you started noticing me,” I choked out as the pieces came together.

All the times his Echoes spotted me. The way he’d zoned out in the library. He started paying attention to me in the Key World after we’d hooked up in an Echo. The threads of his worlds weren’t merely similar. They were interwoven. Like a duet, where the melody and harmony trade places, or the two lines merge.

Like counterpoint.

He touched his lips to my forehead, my eyelids, the tip of my nose. “It took me too long,” he said. “But I’m glad I did.”

He kissed me, sweetly, the sort of kiss that gave more than it took. Something prickled behind my eyelids, and I suddenly understood the biggest difference between this Simon and the others. He knew me. I knew him. Now I was falling for him—not his looks or his hands or the way he felt, but him.

I’d wanted to believe this moment was inevitable. That his feelings for me were so right, so undeniable, he’d fallen for me in two worlds, because the universe wanted us together.

I’d been wrong. Whatever feelings he had for me weren’t because of me, of us, the conversations we’d had and the time we’d spent together. They were residual. A memory of us hooking up in the Echo world. The fabric of the universe mimicking itself and mocking me.

This Simon had never wanted me at all.

CHAPTER THIRTY-EIGHT

CRYING IS USELESS. Crying gets you nowhere, and nothing, and in the end, all you’ve done is waste time and energy when you should have been fixing whatever situation made you want to blubber in the first place.

So I didn’t cry when Simon dropped me off at my house, kissing me without realizing his feelings belonged to someone else. I didn’t cry when my dad came out of his bedroom to check on me. I didn’t cry up in my room, alone with the knowledge that my Walking—my reckless, selfish, stubborn Walking—had turned out far worse than even Addie had predicted.

Instead I gritted my teeth so hard that by morning, my jaw was stiff, my head ached, and I still didn’t have a solution. Talking hurt, thinking hurt, and I wasn’t in the mood to do either anymore.

I’d stayed up past dawn, replaying every moment of my interactions with Simon. No matter how I looked at it, the evidence was clear: The Original Simon was being influenced—guided—by his Echoes. He wasn’t the same person as they were. He hadn’t made the same choices. Left to his own devices, he never would have noticed me. His feelings were grounded in someone else’s memories. He’d never be able to trust them 100 percent, and neither could I.

But Simon understood me in a way that no one else did, saw things in me that everyone else overlooked. I wasn’t sure I was ready to give that up, even knowing the truth. Maybe eventually the self-doubt would ruin us, but for now . . . I couldn’t leave.

If there was a way to separate Simon and his Echoes so he wasn’t influenced by them, his true feelings would surface—and maybe they’d be strong enough that we could make it work.

I was willing to tell myself that, if it meant I could keep him.

But at the root of my fears was one undeniable fact. Simon was more tightly tied to the problems in the Key World than I’d ever guessed. If I was going to free him, I couldn’t do it alone.

Eliot always woke up before me. But I’d never gone to sleep, so for once I had the jump on him. I showed up at his house, coffee in hand, a few minutes after seven in the morning.

“Del!” said Mrs. Mitchell, giving me a hug. “Is my clock wrong?”

“I’m early,” I said. “Is Eliot ready?”

She glanced uncertainly over her shoulder. “I’m not sure he’s awake yet.”

“I’ll get him.” I headed upstairs, throwing open his door. “Wake up, genius boy. We have a problem.”

The lump on the bed stirred briefly.

“Eliot.” I crossed the room and poked at the covers. “Get up.”

“Five more minutes,” he mumbled, and pulled the blanket more tightly over his head.

“I’m not your mom,” I said, setting my coffee down. “And I hope you’re wearing pajamas.”

“Wha—”

Grabbing the covers in both hands, I yanked them straight off the bed and dropped them in a heap on the floor.

“Gah! Cold!”

“Glad to see you’re not naked. I pictured you as a boxers type of guy.”

“Del!” He shot out of bed, no shirt, navy boxer briefs snug enough that I looked the other direction. “What are you doing?”

“Wishing you’d put on some pants.” I kept my eyes closed and listened to the squeak of his dresser drawer. “Can I turn around?”

“It’s ten after seven. Why are you even awake?” He’d put on a pair of sweatpants, but he still wasn’t wearing a shirt.

“We have a problem.”

He took the coffee from me and drank half. “What did you do this time? Hold on. Don’t speak.” He shut the door and sat down at his desk. “Okay. Go.”

“How much do you know about SRT?”

“Synaptic Resonance Transfer?” He tipped his head back, studied the ceiling, and recited as if he had the page in front of him. “Common. Harmless. Confined to Originals and Echoes.”

“What about really extreme cases? Could an Original ever share consciousness with their Echo? Experience what their Echo is doing in real time?”

“SRT that strong would present as some kind of mental illness. Schizophrenia, maybe, or some sort of psychotic break. Trying to process the experiences of so many Echoes would burn out their synapses.”

Simon wasn’t experiencing all of his Echoes’ lives—only the ones who ran into me.

“Theoretically, it’s an interesting problem, but I’ve never heard of it happening,” he said.

Eliot would hear about that kind of thing.

“You think you found someone with advanced SRT?” He scrambled out of the chair, thrilled at the prospect. “That’s beyond awesome, Del. The Consort will love it!”

Somehow I doubted the Consort would look favorably on my actions. I picked up the battered old recorder Eliot kept on his desk, played the first few notes of “Greensleeves.”

“You’re not acting like it’s awesome.” He folded his arms across his bare chest. “What did you do?”

“Why do you assume it was me?”

“Because you’re up at the crack of dawn, you look like death, and you’re about to turn my recorder into kindling.” Gently he pried my fingers off the instrument. “Tell me.”

I sat on the edge of the bed, and he joined me, slinging an arm over my shoulders.

“Remember how I told you something was off with Simon?”

Eliot tensed. “I checked his frequency. There’s nothing special about him.”

“He’s sharing memories with his Echoes,” I said. “Not just feelings. Memories. Entire events. Special enough?”

Eliot whistled, long and low. “He told you this?”

I shifted. “Kind of.”

“Kind of? Did he say, ‘Funny thing, I keep having crazy super-detailed déjà vu’?”

“It came up in conversation.”

“Hell of a conversation,” he said tightly. “Fine. He has SRT. Why is this a problem for us?”

“When I interact with one of Simon’s Echoes, his Original zones out. He thinks he’s dreaming, but he’s actually seeing through his Echo’s eyes.”

Eliot’s face went cool and remote, analyzing my words. “And he’s seeing you.”

I picked at a loose thread on my sweater. “His Echoes notice me. They remember me. When I go back, they ask where I’ve been.”

“Why would you go back?” There was a long, excruciating silence, and then he jerked away from me. “You’re hooking up with his Echo.”

I cringed. “I know, I know. I’m a horrible person. Can we focus on what’s important here, please?”

“This is important. You promised me you wouldn’t Walk by yourself. You gave me your word.”

I covered my face with my hands.

“I don’t understand. They’re not even real.” He sprang up, disgust lacing his words. “Why would you do it?”

How could I explain that the rush I got from being with Simon was nearly as strong as the thrill of Walking? Better, even. When I Walked, I felt free, but the Consort could snatch it away at any moment. With Simon, I was myself, and it was enough, and that was a kind of freedom I’d never had before.

“He makes me happy.”

“Happy?” Eliot’s mouth twisted like he’d tasted something foul. “You risked your entire future for him. Our future.”

“Our future?” I looked at him, misery and betrayal written across his face, feet braced wide and arms folded like he was trying to ward off a blow or hold one back.

“Oh, Eliot.” I pressed a fist against my heart. “I didn’t—” I didn’t know, I’d been about to say, but that was a lie. I hadn’t wanted to know.

“You’ve thought about it. You must have thought about it. We’re good together. We’re an amazing team, Del. Everyone says so. Even you.”

“We’re the best,” I said, cutting him off, afraid to hear any more. We couldn’t undo this conversation. We couldn’t forget it. And I knew, with a sickening certainty, it would change us in ways I never wanted. “It doesn’t mean . . .”

“I’m the best when you need help. When you need someone to cover for you, or fix a problem. I’m good enough to use, but not enough to love,” he spat.

“I do love you,” I said, searching for the balance of honesty and kindness. “Just . . . not that way.”

“No, you save that for Simon. What else are you saving for him? Or did you already give it up?”

“Stop it!” I shoved him, hard.

His mouth snapped shut, and he drew a long, shaky breath. We stared at each other in silence, my chest hollow and aching as if my heart had been knocked out.

Finally he spoke, voice harsh. “Those girls are a game to him. They’re conquests, and now you’re one of them. I hope it was good.”

“He’s not like that.” My own temper reared up then, much more satisfying to hang on to than the guilt and hurt bleeding through me. “And so what if I did sleep with him? It doesn’t make me less. It doesn’t mean I’m damaged.”

“I have been in love with you since first grade,” he said, breath coming fast and shallow. “When you threw up on Tommy Bradshaw’s shoes after he stole my lunch money. More than half my life. I thought if I waited . . . but you won’t even give us a shot, because Simon Lane has some crazy hold over you.”

“I didn’t mean for it to happen. Any of it.”

“You never do.” I flinched, but he kept talking. “He’s going to make you miserable. He’s going to treat you like one of those girls. I won’t fix it. I won’t fix you. Not this time.”

“I never asked you to.” It was like running toward a cliff full tilt and skidding to a stop at the edge, fighting momentum to keep from plunging over into nothingness. I needed to slow us down. To make Eliot see reason. I grabbed for his hand, but he evaded me. I tried again. “I’m sorry. I should have told you about Simon, but I was afraid.”

“You were afraid I’d stop you. Like I could. You don’t listen to anyone else. You don’t think about anyone else. You don’t think about the consequences. You care about yourself, and that’s it.”

I was used to disappointing my family. I didn’t care what my teachers thought. But this was Eliot, hurting and hurtful, and my already-battered heart was breaking into pieces at the sight. I’d done this to him. Useless to cry, I reminded myself, and swiped a hand over my eyes. “Fine. I’m a bitch. But I’m right, too. The anomaly my parents have been looking for is related to Simon. We have to do something.”

He looked at me like I was a stranger. “The only thing you need to do is leave.”

“Don’t make this about us. Please.”

“It’s about you, Del. Same as always. But I’m not interested.” He made a sound like a laugh, only strangled and horrible. “Now you know how it feels.”

CHAPTER THIRTY-NINE

ELIOT AVOIDED ME at school all morning, so I wasn’t surprised when he was a no-show at lunch. I sat at our usual table anyway, endlessly twisting the metal tab on my Coke. I was as selfish and self-centered as he’d said. For years, he’d dropped hints but I’d ignored them or laughed them off because they’d made me uncomfortable. Because he was my dearest friend, but only a friend, and telling him so might have ruined us.

Now we were beyond ruined. I didn’t know how to make it up to him. The one thing he wanted was impossible for me to give.

People milled around the cafeteria, and I watched as they made choice after choice, world after world, ignorant of the weight their decisions carried. I didn’t know whether to envy them or feel sorry for them. Could I have chosen differently? Eliot and I made a great team, but I’d never thought of him that way. He’d never made my heart skip and my head swim the way Simon did.

But I could have been honest.

I pressed the heels of my hands against my eyes, trying to relieve the aching behind them, and took a shuddering breath.

“Missed you this morning.” Simon’s voice came from overhead. “I thought maybe you’d disappeared.”

I opened my eyes, my pulse kicking up at the sight of him. “Right here,” I said, smiling despite myself.

He dragged a chair over and straddled it, folding his arms over the back, all easy confidence and long limbs. “Are we good?”

When I nodded, he surveyed the table, empty except for my can of pop. “This is not a proper lunch.”

“I’m not hungry.”

“Guess not. Where’s Eliot?”

I couldn’t get the words out, but he must have understood, because he stood up and tugged at my hand. “Come on.”

“You wanted to sit with the jocks?” I eyed the table brimming with letter jackets and school spirit.

“Another time. Today you need a break.”

We’d gone only a few feet when Bree stopped us.

“Hey, stranger.” She gave Simon a friendly push, but her smile was strained. “Duncan wants to talk to you about some sports boosters fund-raiser. Got a minute?”

Simon’s hand tightened on mine. “Not right now. Sorry.”

“But I saved you a seat,” she said, a plaintive note to her voice.

“Give it to someone else,” he said gently, and led me away without waiting for her response.

I blinked. “You didn’t need to—”

“Yeah, I did.”

I felt the stares as he led me through the maze of tables and out the side doors, but Simon didn’t seem to care. What must it be like to be so sure of yourself and your place in the world? I’d thought I had that, once, but my certainty had unraveled weeks ago.

“Where are we going?”

“Equipment room,” he said. “Nobody’s in there this time of day.”

I stopped short and gave him a dubious look.

“It’s the only place in the building where we don’t need a hall pass. I’m in there all the time for team stuff, and since I’m captain . . .” He reached into his pocket. “I’ve got a key.”

He looked so pleased with himself I decided not to mention I didn’t need a key.

“How’d you end up as captain when you’re only a junior?” I asked. “Isn’t it usually for seniors?”

“My cocaptain’s a senior,” he said, and pointed at the trophy case nearby. “But I was on varsity last year, and we won State, so . . .”

He kept talking, but something in the display caught my attention. I eased closer, nodding as if I were listening.

One of the net-draped trophies winked out of existence, replaced by a smaller, far less showy one. In an instant they swapped again, and everything looked exactly the way it should.

Another inversion in the Key World. Another one connected to Simon.

“I just remembered,” I said, smacking my forehead. “I have to turn in a library book.”

“Now?”

“It’s way late. Fines in the double digits, and the librarian’s threatening me with another detention.” I shooed him off. “You go ahead and I’ll catch up.”

The frown cleared. “Del, chill out. I wasn’t going to put the moves on you. At least, not a lot.”

“I’m looking forward to your moves. I’ll meet you in a few minutes.”

Easy enough to say I got caught without a hall pass, or that the librarian had made me shelve books as a way to pay off my fine. I’d come up with a story, but for now, I needed to get rid of him.

Reluctantly he let go of my hand. “Go on,” I said, shoving at him. I made a show of heading in the opposite direction, toward my locker, glancing back to check his progress.

Once he was safely out of sight, I raced back, shielding the trophy with my body. My pulse drummed in my ears as I pulled out the lock picks and got to work. With any luck, the few passersby would think I’d suddenly become a basketball fan.

As soon as the lobby was empty, I shoved the panel of glass aside and reached for the blinking net, listening for its shifting pitch.

Nimble fingers, open mind. I caught the frequency on the second try, drawing it closer, out of the display case. With light, careful movements I enlarged the pivot enough to squeeze through.

One last check around the deserted lobby, and I stepped into the rift, holding my breath at the tight fit.

When I emerged on the other side of the pivot, the trophies were smaller and the room was dotted with people who took no notice of me. One look at the team picture explained the difference. Simon had never moved up to the varsity squad, and the team had never made it to State.

If the inversion took root in the Key World, would my Simon lose his place as captain? Would people treat him the same way? Would he forget me again? I wasn’t sure how he’d be affected, but it wouldn’t be good.

I touched the trophy, trying to find the strings that contained the inversion. Over and over, my fingers slipped. My hands ached from searching so meticulously through the threads, testing each one without altering it, and my head pounded. No wonder my dad had contracted frequency poisoning.

My shaking fingers snagged on a thread, and I froze. If even one line snapped, it could cause another cleaving. I had to empty my mind of everything—Simon, my dad’s illness, the anomaly threatening the Key World. The only thing I could think about was finding the bad strings.

Nimble fingers, open mind.

And there they were. Once I found the first, the rest were easy to locate. I coaxed them back into tune, painfully aware that the filaments beneath my fingers were connected to this Echo’s Simon. I wondered how my actions would alter him, if it would cause him to choose differently, or nullify the decisions he’d already made. It was too much power for one person to have over another, Echo or Original.

The frequency shifted, a grinding, grating, reluctant drop, and I checked my watch. Not bad for fifteen minutes’ work.

The empty lobby was both a surprise and a relief. Both the net and trophy were back in place, resonating at the Key World frequency, exactly as they should be. I slid the glass door shut and reached in my bag for the pick that would relock it.

“If you wanted to see it up close,” Simon said, stepping out from behind the vending machine, “all you had to do was ask.”

CHAPTER FORTY

THERE ARE THREE reasons Walkers are almost never caught:

They’re good.

They’re careful.

People don’t pay attention.

As long as you had two out of three, you could usually escape detection. I was good, but not careful. And Simon was definitely paying attention.

Basically, I was screwed.

“Don’t we have a date in the equipment room?” I said, scrambling for a distraction, hoping he hadn’t seen the truth.

One look at his face dashed those hopes. “Nobody who cuts class as often as you worries about library fines. Did you really think I was going to buy that story?”

I lifted a shoulder. “Saying yes doesn’t make either of us look good.”

“None of this makes you look good, Del. Start talking.”

“It’s complicated.” The idea of telling him made my stomach roil.

“So talk slow. Use small words. But start talking, because what I saw was impossible.”

“Nothing’s impossible,” I murmured, but he folded his arms and stared until I caved. “Can we do this somewhere else?”

“Equipment room,” he said grimly. “The truth this time. All of it.”

You don’t think about anyone else, Eliot had said. You don’t think about the consequences. He was right. It had been the Walking that mattered most, not the worlds I found. But now I’d found Simon. Irresistible, inexplicable, problematic Simon.

Walkers valued the Key World above all else, but secrecy ran a close second. We’d had it bred into us, generation after generation passing down the gene for Walking and the warning to keep it hidden. Could I really betray that trust for a boy? I ran through a million stories as we headed to the equipment room. Surely one of them would be more believable than telling him the truth. Safer, too. If the Consort discovered I’d told, they would come after us both.

Most lies aren’t meant to ruin; they’re meant to protect what we hold most dear, whether it’s a person or an idea or a way of life. But even the noblest lie eats away at the truth, until you’re left with the facade and what you were protecting crumbles to dust.

I could lie, and save Simon, and myself, and the Walkers’ secret.

And in doing so, I would lose him.

When we reached the equipment room, just inside the field house doors, he gestured to the dead bolt. “Did you want to take this one, or should I?”

“Be my guest.” My hands were shaking too hard to turn a door handle, let alone pick a lock.

The equipment room was actually a big closet—high ceilinged and windowless, smelling of rubber and dust. There were carts of basketballs and volleyballs, towers of plastic cones, and hockey sticks corralled in a trash can, ends sticking up like the bristles of a brush. A single fluorescent light fixture buzzed overhead, too dim to reach the corners.

He closed the door and leaned against it, the implication clear: We weren’t leaving until he got answers.

“Nice place,” I said, boosting myself onto a waist-high stack of gymnastic mats. “You bring a lot of girls here?”

Once again he looked at me with too much perception. “Wouldn’t be much of an escape if I did.”

“Makes sense.”

“More than I can say for you,” he said.

“Tell me what you saw.”

His expression hardened. “So you can make up a story to match?”

“Simon, please. I’ll tell you the truth. I’ll answer your questions. But it’ll be easier if I know what you saw.”

“I am not interested in making this easy for you.” He rubbed the back of his neck wearily. “You were lying about the library book. I thought it was because you were nervous about coming in here, so I started to follow you, to tell you we could go somewhere more public. When you turned around, I hid behind the vending machines and waited to see what you were up to. You’re pretty handy with a lock pick,” he added. “Are you some sort of teen superspy?”

“Really not,” I assured him. “What next?”

“You know how in the desert, the heat makes the air shimmer? You reached into the case, and the whole thing kind of . . . rippled, and you walked toward it. But instead of running into the wall, you disappeared, a little at a time. Like you were a mirage.”

He must have thought he was losing his mind. He was astonishingly calm for a person who had to be questioning his sanity, though. “What did you do?”

“I poked around, but everything looked normal. The only reason I didn’t think I’d dreamed it was because the trophy case was open.”

“What kinds of trophies were inside?”

“The ones I was telling you about. When we won State.”

“You’re sure? Did you actually see them? Or are you remembering?”

“I’m positive. I straightened the net on top.” The inversion hadn’t caused any permanent damage. At least one part of my day had gone right. He continued. “When the air started to move again, I hid. Thirty seconds later, you were back.”

“You didn’t tell anyone else?”

“Who would believe it?”

He had a point. The question was, would Simon believe me? I was surprised by how much I wanted him to. I should have felt only fear, but somehow it was tempered by a sense of relief that I could finally come clean.

“Everything I tell you has to stay secret,” I said. “You cannot even begin to imagine the trouble we’ll be in if they find out I told you.”

I could imagine it perfectly. Permanent expulsion. Thrown in an oubliette. I’d never see him again. But the risk of losing him, of going back to a time when he looked past me as if I were an impression, was equally awful.

“They?” he asked.

I swallowed. “My family. My . . . people, I guess you could call them. Do you promise?”

“Not to tell anyone that I’m hallucinating during second lunch? Done.”

I wiped my sweaty hands on my jeans and dove in. “When you play basketball, do you ever wonder if the game could have gone a different way? Like, what if the lineup changed? Or if you’d called a time-out instead of playing through? Taken a shot instead of passed the ball? Do you ever wonder what would have happened if you’d made different choices?”

“Sure. Everyone does.”

“Not me. I don’t have to, because I can see it.”

My words started out halting and low, wilting in the face of his skepticism. But my need for him to believe me was greater than my fear, and I used that need to lend my voice strength.

“Every time you make a decision, from what you had for breakfast to who you fall in love with, the universe splits in two. One half is the part you remember. It’s real. That’s the decision you made. The other half is the what-if.”

“Like parallel worlds,” he said with a frown.

“Yes. Except, this is the only one that counts. We call it the Key World.”

He opened his mouth and closed it again.

“The other worlds are called Echoes. They’re filled with copies of people, and those people make more choices, and their choices make more worlds, and it goes on and on. For infinity. Sometimes the Echoes cause problems, and the Walkers—my people—have to protect the Key World.”

“You’re crazy.”

I was a lot of things, most of them bad. But crazy wasn’t one of them. I hopped down from the mats and stalked toward him. “Then what did you see?”

“You cut class to visit parallel worlds. You’re actually telling me that.”

“I’m telling you there are entire worlds out there, ones you can’t imagine. Worlds where we’re still British subjects. Worlds where penicillin was never invented. Worlds where women never got the vote, or the Beatles never broke up. It’s not even big choices, sometimes. In sixth grade I took a field trip to a world where Texas seceded because someone forgot to send a telegram.”

He shook his head. “This is a joke. You’re taping me, and you’re going to upload the video.”

“Do you see any cameras?”

His face softened, turned sympathetic. He took my hands in his. “You’re upset.”

“Of course I’m upset. I’m not supposed to tell people like you. Hell, there’s now a world out there where I didn’t tell you.” There were worlds where Simon hadn’t caught me. But those Echoes wouldn’t last, because I couldn’t sustain them—and there was something painfully ironic about that fact. Now that I’d told him the truth, it felt inevitable, like we’d been guided to this moment by the same universe that had twined us together in the first place.

“Is there a world where you and Eliot didn’t fight?”

There were worlds where Simon hadn’t chosen me. There were worlds I hadn’t gone after him. But Eliot and I lived in this world. No Echoes, no second chances, no way around the fact I’d broken his heart. I felt sick at the thought. “It’s more complicated than that.”

“It’s really stressing you out, isn’t it? Have you tried talking to him?”

I yanked my hands away. “You think I’m making this up because of Eliot? You think I’m delusional because we fought? That’s the stupidest thing I’ve ever heard. You asked me for the truth, and I’m telling you. I’m a Walker. What you saw was me Walking to another world, fixing it, and coming back.”

His sympathy vanished. “Prove it. Take me with you.”

I recoiled. “That’s impossible.”

“Nothing’s impossible,” he mimicked. “Isn’t that what you said before? Teach me how to Walk to one of these other worlds.”

I couldn’t teach Simon how to Walk any more than I could teach him to fly. “It’s a genetic condition. You can’t do it if you aren’t born into it. And you weren’t, trust me.”

“How do you know?”

“Remember how you keep saying I’m a music prodigy? It’s a Walker thing.”

“I suck at music, so I’m not allowed to go with? That’s crap.”

“That’s life,” I said, Monty’s words coming back to me. “I didn’t say it was fair. Trust me, that’s one of the first things we learn. Life isn’t fair. The good guys don’t always win. There are plenty of worlds where the human race is better off, but we don’t get to pick and choose. Our job is to protect the Key World. Anything else is gravy.”

“Fine. Do it again, and I’ll watch.”

I started to protest, but he cut me off. “Either you’re crazy, or you’re lying, or you’re for real. But only one of those ends up with us leaving this room together, Del. Your choice.”

My shoulders dropped. “Am I going to come back and find the school psychologist?”

“I promised you I wouldn’t say anything. I keep my word.”

“I’m crossing over and coming straight back. If you’re not here . . .” I couldn’t think of a dire enough threat. Anything I could imagine was child’s play compared to what the Consort would do.

“I’ll be here,” he said.

I closed my eyes and listened for a pivot. A freshly formed one hovered less than a foot away. It must have sprung up when he’d decided to hear me out.

“Ready?” I asked, opening my eyes to find him watching me. It was a physical sensation, sweeping over me from my forehead to my toes and back again, turning my entire body to pins and needles. I felt oddly exposed as I reached for the pivot, its edges sharp as a paper cut. Even after everything I’d revealed, it was terrifying to let him see this part of me.

The weight of Simon’s gaze propelled me through the rift.

The equipment room stood deserted, the door swinging wide. I heard a slam and peered out at the empty field house. His Echo had left, true to his word. Even without the dissonance, this was not a world I wanted to stay in.

I ducked back through and crashed into the broad planes of Simon’s chest. His arms wrapped around me, and I soaked up the sound of the Key World streaming from him like sunlight.

“I thought I could find it.” He looked down at me, pupils huge and astonished. “I figured I’d follow you through. But you . . . vanished. You left.”

There was something in his voice beyond surprise. Bewilderment, maybe, and hurt.

“I came back.”

“You came back.” He kissed me softly, and then less softly, and then he was backing me toward the mats I’d been sitting on, his hands woven through my hair, my hands sliding along his back. “It’s real. It’s amazing, Del. You’re amazing.”

“Glad you finally noticed,” I said between kisses.

If this was what happened when you were honest with people, I’d have to try it more often.

Then again, I wasn’t being entirely honest. I didn’t tell him that he was sharing memories with his Echoes, that I’d kissed him in other worlds. Too much at one time, I thought, feeling liquid and golden from his touch. Better to tell him when I understood what had happened.

The muffled sound of the bell stopped me from saying anything else. “Class,” he said against my neck.

I touched my swollen lips, envisioning Eliot’s reaction when he spotted us. This room was a refuge, a world of its own, and I didn’t want to leave. “Let’s skip.”

He stepped back, but left his palm curved around my side. “Coach benches us if we cut. Can I see you later? After practice?”

His mouth came down on mine, silencing the whisper of doubt inside me. Later, I’d tell him about his Echoes. We’d figure out how to free him from the anomaly. We’d start fresh. We’d be happy. Simon’s kiss made it all seem possible, the choices before us as limitless as the multiverse itself.

“Sounds good,” I said, and let myself believe.

CHAPTER FORTY-ONE

IT WAS EASY to think I’d done the right thing with Simon whispering those exact words in my ear. But as the day wore on, doubt crept back in. I’d told an Original about the Walkers. I’d let him see me Walk. I was still keeping secrets from Simon, and Eliot was still avoiding me.

It was probably for the best. I could only imagine what Eliot would say if he knew I’d told Simon about us. He’d probably turn me in to the Consort himself. Maybe he already had.

When I arrived home, Mom was waiting by the kitchen island with her coat on, a giant leather tote at her feet. Her shoulders sagged with relief.

“Del! Where have you been?”

“School. Like every other weekday. Am I in trouble?” Guilt surged, and I turned away, fumbling with my coat and scarf.

“I’m in a hurry. The Consort needs me to come in right away, Addie’s at her apprenticeship, and I didn’t want to leave your grandfather alone.”

“I can hang out with him.” In the family room, Monty was watching a documentary on the History Channel, arguing with the narrator about the outcome of the Korean War. “How long will you be gone?”

“We should be back by dinner. Addie said she’d be late too, so you’re off the hook for training tonight.”

At least Simon and I would have some measure of privacy.

“I’ve got to run, sweetie. Bye, Dad. Love you both.”

Monty joined me as I made a cup of tea. “How was your day?”

“Strange.” I wrapped my chilled hands around the mug. “Simon’s coming over later to practice our composition.”

“Was it him who put those roses in your cheeks?” he asked with a grin.

I touched the side of my face, and the loneliness of my trip home faded. “Maybe.”

“It’ll be good to see this young man up close, considering how much time you’ve spent with him.” He winked. “And his Echoes.”

I stared into my mug. “I should have known better.”

“Bah. People will do all sorts of things for love. You can’t blame them for it.”

“I’m not in love with Simon.” I wasn’t quite ready to confess the extent of my feelings—or my actions. Not even to Monty, who’d been paying closer attention than I realized. “There’s something different about him.”

“I don’t doubt it,” he said, and patted my hand. “Not to worry. I’ll keep your secrets and you’ll keep mine.”

I hoped so. I leaned back against the island and checked him over. Neatly dressed, hair combed, lucid despite his ongoing argument with the television. One of his better days, and I hoped it held. “You’re not going to hover, are you?”

He shot a mournful glance toward the empty cookie jar. “Your mother hasn’t made cookies in ages. Did you notice? Oatmeal chocolate chip would hit the spot.”

I was not in the mood to bake. “Why don’t I fix you a bowl of ice cream?”

“Too cold for ice cream. Rose made sure to keep oatmeal chocolate chip in the house. We never went without. Your mother uses her recipes. Did you know that?” His eyes went distant, his voice wavery. “I wonder if she has some right now. If she’s making them wherever she is.”

Hard to tell if he was genuinely confused, or putting on an act to get what he wanted. But real or feigned, the last thing I needed was Monty slipping in front of Simon. If an hour of baking would buy me a peaceful afternoon . . . “Cookies it is.”

By the time Simon rang the bell, the island was covered with racks of cookies and Monty was at the table with a plate full of crumbs and a glass of milk, seemingly content.

“I’ll get it,” I said, brushing at a lock of hair that wouldn’t stay tucked into its braid.

Monty made a noise of agreement and helped himself to another cookie. I’d lost track of how many he’d eaten. My mom was going to kill me.

The minute I opened the front door I forgot about my mom and sugar comas. Simon, rangy and lean and breathtaking, crowded out everything else.

“Hey.” I didn’t know what to do with my hands. Was I supposed to hug him? Kiss him? I wanted to melt into him, but with Monty down the hallway, it seemed like a recipe for disaster. “How was practice?”

“I was distracted.” He set his backpack on the floor, midnight eyes crinkling at the corners. “You have stuff on your face.”

“Flour.” I swiped at my forehead. “I was baking.”

He sniffed the air appreciatively, and rubbed his thumb slowly over my cheek.

“Did I not get it?” My voice sounded too breathy.

“You did.” His fingers curved around my neck and he touched his lips to mine.

I figured out what to do with my hands: slide them over his shoulders, pull him closer. His hair was damp from the shower, his skin smelling soap-and-water clean. He tasted like toothpaste and mischief. With one hand he unwound my braid, while the other slid along the strip of bare skin above my jeans.

Whatever trouble we were in was worth it.

“You must be Del’s friend,” Monty said from the kitchen doorway.

Simon froze. “I thought you were home alone,” he said against my mouth, and straightened.

“Simon Lane, sir.” He took a full step away from me and extended his hand.

“Montrose Armstrong. I’ve been wanting to meet you for quite a while.” He held the handshake for a beat too long, reading Simon’s frequency. I tried to interpret his expression. If there was a problem, Monty would feel it.

Finally he let go, nodding in approval. My lungs resumed working. “Del’s my favorite, you know.”

Simon’s hand rested on the small of my back. “Mine too.”

“She made cookies,” Monty said. “You should have one.”

I glared at him, but we went into the kitchen, where Simon made enthusiastic noises about the cookies and I plotted our escape.

“You two are working on a song for music class?” Monty asked.

Simon finished the cookie before responding. “I lucked out, getting paired with her. She’s a genius.”

“You’re not musical?” Monty sounded surprised.

“No, sir. But Del says it runs in your family. Being good at music, I mean.”

“Told you that, did she?” Monty said vaguely, but his gaze sharpened.

“We’d better get to work,” I said, and dragged Simon to the living room.

“Is he one too?” Simon whispered. “A Walker?”

“Everyone in my family is. Eliot, too. But Monty . . . he’s done it for too long. He’s not quite right now.”

He sat at the piano. “Seemed fine to me.”

“He has good moments and bad ones,” I said. “And he made a special effort for you.”

“Am I special?” He hooked a finger through my belt loop.

“Very,” I said, giving him a slow smile.

“I thought about you all day. About this. It doesn’t seem possible.”

“Anything’s possible.”

His hands closed tightly over mine. “Is there’s a world where they’ve cured cancer?”

My smile fell away. “I don’t know. Probably. But . . .”

“Could we take my mom there?”

I couldn’t look at him, at the hope shining in his face, knowing I would be the one to snuff it. “She couldn’t get through,” I said. “Like when you tried following me. If you’re not a Walker, you can’t cross.”

The shadows under his eyes deepened, but he rubbed a hand across his face and tried again. “What about bringing the medicine here?”

Breaking news gently is a misnomer. News doesn’t break. People do, no matter how you try to cushion the blow.

I tried anyway, more careful with my words than ever before. “Bringing objects over from Echoes is forbidden. It’s too dangerous.”

He scoffed. “It’s medicine. How dangerous could it be?”

I thought about the drawing his cemetery Echo had given me, how blithely I’d tucked it into my backpack. Even now, hidden in a dresser drawer, the faintest trace of dissonance drifted from it. But the sketch was a reminder, not a catalyst.

“It’s not the size of the object; it’s the change it creates, and there’s no greater change than someone’s existence. An alteration that big is against the rules.”

He dropped my hands, shocked and furious. “You won’t save my mom because you don’t want to get in trouble?”

My anger rose to meet his. “I can’t. If I gave her medicine from an Echo, the difference in frequencies might end up hurting her.” I thought about the anomaly, the plague of inversions, the way Simon seemed to be caught in it. “It could rip her apart. And the damage could spread. To you, to anything or anyone she comes in contact with. You could fade right out of existence, and I’m not doing that to you again.”

He went very still. “Again?”

I ran my fingers over the cool ivory keys and said nothing.

“Del?”

For a place that wasn’t real, Park World managed to ruin every part of my life. “I’m not grounded. I’m suspended from the Walkers. Addie and I went out a few weeks ago, to an Echo that was really unstable. You were there with Iggy. I messed around with the threads, and . . . they broke. I cleaved the entire branch.”

“Cleaved?

“Like pruning, only the branch . . . disintegrates.” I sank onto the bench next to him.

“I disintegrated?” His laugh sounded nervous, the kind that preceded a complete freakout.

“Your Echo did. You’re an Original. You belong to the Key World, so it didn’t affect you. But if we start bringing stuff over from other branches, and it damages the fabric of this one, especially around your mom, you could unravel too. Both of you.”

I touched my forehead to his shoulder. The muscles beneath his T-shirt were clenched and unyielding. “I’m so sorry. I wish . . .”

“Don’t,” he said. I flinched at the harshness in his voice. “What good is it, then?”

A chill crept over me. He’d thought Walking was amazing, in the equipment room. He’d thought I was amazing.

I can’t figure you out, and I want to. Now he had, and I wasn’t a puzzle, or the girl he’d kissed in the rain and in dreams. I was a means to an end.

But hadn’t I done the same? I’d used Walking to get what I wanted but couldn’t have.

“What’s the point if you can’t save people? Make the world better?”

“Walkers believe that the integrity of the Key World matters more than anything,” I said. “It’s the only world strong enough to sustain the weight of all the choices that spring from it. It’s like the trunk of a really big, really ancient tree, and all the other worlds are branches.”

“The world is a tree. Great. Very green.”

“If the branches are damaged, and it spreads, the tree gets weaker. If it happens too many times, the tree won’t survive. So we try to contain the damage, as much as we can, but sometimes that means letting bad things happen.”

“That’s crap. She’s my mom.” He took my hands again, and I wanted to weep at the desperation in his words. “You said it might hurt her. That means it might not. Anything is better than her odds right now. Please, Del.”

“I can’t.”

“You can. You break rules all the time. You broke one today, telling me about the Walkers. Why not now, when it might actually do good?”

I felt myself weakening, the wave of his sorrow battering my resolve. My gaze fell on our composition, the notes he’d borrowed from his Echo, the song we’d made together a reminder of all I’d done wrong. I shook my head, finally understanding what my parents had been trying to teach me. “I’m so sorry, Simon. Just because something’s possible doesn’t mean we should do it.”

Turns out, telling your almost-boyfriend you won’t save his mother’s life puts a damper on the relationship. He left a few minutes later, distant and wounded and avoiding my eyes.

I didn’t blame him, exactly. But I doubted him. I doubted myself, for confiding in him, for believing in us.

“Delancey!” called Monty from the kitchen, moments after Simon left, pulling the door shut with a solid thunk.

“Please don’t tell me you’re hungry again,” I said.

Monty sat at the island playing a phantom tune, his fingers gnarled but certain on an imaginary keyboard. “You told him about us.”

Too wrung out to bother with denial, I said, “He saw me Walk. I didn’t have a choice.”

His eyebrows lifted, two furry white caterpillars arching in unison. “He left in an awful hurry. You two have a falling out?”

“His mom is sick. He wanted me to bring back a cure from the Echoes.”

“From the look on your face, I’d guess you told him no.”

I picked up one of the cookies, but my stomach rebelled. “What was I supposed to tell him? We don’t know what could happen, especially with the anomaly causing so many problems. He doesn’t understand what’s at stake.”

“Does anyone? You toss around the word ‘infinity’ like you know what it means, but you’ve not the faintest idea. None of us do. Whatever you imagine, whatever you think you know, infinity stretches farther. It’s a bit like people. They’re capable of so much more than they realize.”

I broke the cookie in half, and in half again, until crumbs showered the countertop. “He’s never going to speak to me again.”

“Bah. Do you trust him?”

Underneath the hurt and the doubt, the answer was as clear as the Key World. “I do. There’s something about him . . . I don’t know what it is, but he matters.”

“I don’t doubt it. And if there was a way to save his mother without risking the Key World, would you?”

“Of course.”

“Tell him so. And then find a way to do it.” He twinkled at me. “Infinity, Del. Anything is possible.”

CHAPTER FORTY-TWO

DESPITE MONTY’S PEP talk, I wasn’t ready to tell Simon anything. I was a collection of hurt feelings and unanswered questions. Better to go to him when I had something worthwhile to offer. Something more than myself.

Over dinner, everyone was subdued, lost in their own thoughts. “Things didn’t go well with the Consort today?” Addie finally asked.

“We’re not making the progress we’d like,” my mom said.

“I did some research today,” Addie said. “I have a theory about the anomaly.”

My mom set her fork down. “I thought we made it clear that you were to stay away from the situation.”

“You did. But Councilman Lattimer thinks I could be helpful.”

Monty made a face like a petulant child.

“Delightful,” Mom said. “Did a member of the Consort give you express permission to involve yourself with a classified situation?”

“Not exactly,” Addie said. “But I thought . . .”

My dad said, more kindly, “It’s nice that you want to help, honey. But this isn’t a school project. We need you to focus on your apprenticeship and keeping your sister out of trouble. Leave this to the adults.”

“The adults?” Addie said faintly.

Mom shook her head. “I expect this kind of behavior from Del, Addison. Not you.”

Addie’s face went white, then red, then white again. “May I be excused?”

She left without waiting for an answer. Monty tsked. “She’s not a child.”

“She’s my child,” Mom replied. “I’m not putting her in harm’s way if I can avoid it.”

“Can you?” he asked softly. “Desperate times, Winnie.”

“Not that desperate. Not yet.” She swallowed, reached for my dad’s hand. “The girls are to stay away from anything having to do with the anomaly. That’s our decision, and it is final. Are we clear?”

Monty nodded slowly, looking smaller, and I felt a twin rush of emotion: sympathy for him, irritation with my parents. Without speaking, I cleared my place at the table.

“The same goes for you, Del,” my father said. I stared at the floor. “The last thing you need is to be caught defying the Consort.”

“Got it,” I said.

I had no intention of getting caught.

Upstairs, Addie was lying on the bed, eyes closed, headphones on. I sat down next to her and plucked them off. Rachmaninoff came through the earbuds, tinny and strident.

“They’re worried,” I said. “They’re so worried they can’t hear anything else.”

“Whatever,” said Addie. “You get away with crap constantly. Why not me? Not even once?”

“You got caught because you told on yourself,” I said impatiently. “When we broke into Mom’s office, I locked it up again and kept my mouth shut. I didn’t sit down at dinner and say, ‘Hey, Mom, you need to invest in a better lock, because I picked yours in under ninety seconds.’ You don’t want to get caught, learn how to be sneaky.”

She opened her eyes. “Oh, good. I’m taking advice from a delinquent. This is what my life has come to.”

“A very successful delinquent, who’s willing to teach you her ways,” I added, and hit her with a pillow. “Tell me your theory.”

“We’re supposed to leave it alone.”

“You’re supposed to be teaching me,” I said. “Consider this a teachable moment.”

She snorted, but sat up. “Fine. I think they’re approaching the whole problem backward. The Consort’s looking for the anomaly in the Echoes—moving from newer to older, smaller to bigger. But the biggest, oldest world is this one.”

“You think the source is here? The Consort would have found anything that disrupted the Key World.”

“You know the Queen Anne’s lace in the backyard? It’s a weed, technically. An invasive species.”

As a kid, I’d picked enormous bouquets of Queen Anne’s lace—broad white crowns and spindly stems that left my fingers smelling like carrots. “It’s a flower. Not a very pretty one though.”

“It’s a weed. We’re used to it, so we don’t think about pulling it when Mom tells us to clear the flower beds. But she’s got enough other plants back there that it doesn’t take over. The Key World is the same way: Even if the anomaly is here, our world is stable enough to keep it in check. But the Echoes aren’t as stable. There’s room for it to take root, and each Echo generated from one of the infected branches is even more infected. It’s cumulative.”

“But what about here? Would it affect Originals?”

“You mean Simon?” She rolled her eyes. “It’s more likely to affect his Echoes. He’s popular at school, right?”

“He’s popular everywhere. You’ve seen him.”

“Some people are natural pivot points. The Consort physicists haven’t studied it super closely, but they’ve found that a small segment of the population has a tendency to form significantly more branches than others.”

I thought back to the maps Eliot had shown me, thickets of lines crowding around the Key World. “Why would that happen?”

“We don’t know. It’s like their decisions have more resonance. Historically, those people end up in positions that underscore those tendencies—they become politicians, or prominent in a given field, or celebrities. If that’s the case with Simon, he’s popular because he’s a pivot. He literally can’t help it.”

“That’s crazy. Does it make them less stable? Do they have SRT?”

“It doesn’t affect their stability. They’re like any other Original.” She paused. “They do display a higher rate of SRT, but that’s simple math—more Echoes means more chance of an overlap.”

More Baroque events, too. Situations with lots of choices meant lots of Simons, operating on similar frequencies. If they overlapped, it would account for his extreme SRT. And more Simons meant he was more likely to be affected by the anomaly.

But unless I wanted him to end up as the Consort’s guinea pig, it was smarter not to mention that to my sister.

“So, what’s next? If we’re going to figure this out, we need a plan.” Nothing distracted Addie like a plan.

She reached for a nearby map, then tossed it aside. “First thing is to find the branches that are being affected. Eliot can help us narrow it down, can’t he?”

My voice sounded small. “I don’t think Eliot’s interested in helping me right now.”

“Why not?”

I traced the floral pattern on the duvet.

“I see,” she said. “Give him some time. He’ll come around.”

Time wasn’t the answer. But all I said was, “I’ve got a copy of the software we can use.”

Addie looked relieved. “Excellent. Between the anomaly and the cleavings, none of my maps are working. Fork it over.”

I had an instant of panic Simon would text me about Walking while she was using it. Then I shoved my paranoia aside. He wasn’t going to be texting, or calling, or acknowledging me anytime soon.

“This software is awesome, Del. I don’t know why you won’t give Eliot a chance.”

“On the strength of his programming abilities? He’s my friend. I don’t think about him that way.”

“You might if you tried.”

“Could you make yourself fall for someone you didn’t want, just because it would make life easier? Find some nice Walker guy instead of a nice Walker girl?”

“Point taken.” She cocked her head to the side. “There’s a pivot in your room.”

My hands went cold. “There are pivots all over the house. No big deal.”

“This one’s strong.” She headed for the stairs. “Someone must have used it recently.”

“I bet it’s a glitch.” I scrambled after her. “Eliot hasn’t finished debugging the code.”

She ignored me, and I had a horrible, slow-motion sense of watching disaster unfold. She threw open the door, wrinkling her nose at the mess of papers and clothing scattered everywhere. Map in hand, she turned in a circle until she found the pivot. It pulsed loudly, a drumbeat announcing my guilt.

“Tell me you didn’t.” She stalked toward the rift.

“I didn’t!”

She stopped in her tracks and faced me dead-on. “Tell me the truth.”

I looked away.

“Oh, my God. You’ve been Walking behind my back? Using this to sneak out and . . . what? Mess around in the Echoes? Were you trying to make me look bad?”

“No! Why would I do that?”

“I don’t know, Del. I don’t know why you would violate your probation, and risk your entire future, and lie to the Consort, and . . . You’re crazy. That’s why. You’re insane. They don’t let crazy people Walk, you know. It won’t matter if you score one hundred on the exam. They’re never going to give you a license.”

I knotted my fingers together. “They will if you don’t tell.”

“Lie for you.” She scoffed. “You’ve definitely lost it.”

“You don’t understand,” I said, desperation flooding me. “Addie, please.”

“I understand you’re a lying little weasel. I’ve been wasting my time babysitting when I could have been helping Mom and Dad. I put my own reputation on the line. I told Lattimer he should consider ending your suspension early, that you were a lock to pass the test. I told him you’d learned your lesson.” She laughed. “We’re both idiots, I guess.”

Addie had backed me up with Lattimer?

“You never told me.”

“I didn’t want to get your hopes up. Unlike you, I don’t lead people on. Make them believe something that was never true. Like me, thinking you’d changed.” She waved the phone at me. “Or Eliot, thinking you cared about him.”

I snatched the phone back. “Leave him out of this.”

“What did you do to him? Eliot would walk through fire for you, so it must have been something big. Was it because you were Walking without him? Or did he get sick of your weird obsession with Simon Lane?”

I forced myself to look away from the pivot.

“It’s both,” she said softly. “Simon and Walking. You were chasing after his Echoes. That is . . . pathetic.”

“You can’t prove any of it,” I said, fear turning ugly and vicious inside me. “Nobody’s ever interested in your theories, Addie.”

“I’ll find proof,” she said, heading toward the stairs. The smile she leveled at me was as brilliant and hard as a diamond. “And once I do, I will bury you.”

CHAPTER FORTY-THREE

I STOOD IN my empty room, the pivot throbbing in time with my head. How long before Addie tracked down the proof she needed? My first instinct was to call Eliot, but he wasn’t an option anymore. My second was to ask Monty for help, but when I found him, he was sitting in the living room while my parents washed dishes ten feet away.

I was running out of choices—and time.

“I’m going out,” I called.

Mom turned. “It’s nine o’clock at night. Where are you going?”

“Eliot’s.” The lie rolled easily off my tongue.

From the living room, Monty broke into a coughing fit. “Aren’t you going to say good-bye?”

I gave him a quick hug. Before I pulled away, he pressed something into my hand, curling my fingers around it. “Just in case.”

It was a small silver pendant, a tuning fork like Addie and my mom had. I wasn’t supposed to have one until I got my license. “Thanks, Grandpa.”

“Use it well.” He settled back into the recliner, eyes shut.

“It’s a school night,” my dad reminded me. “Be back by curfew.”

Making curfew was the least of my worries.

I’d left origami stars behind in every Echo I visited, and they were still resonating at the Key World frequency. But instead of guiding me home, my breadcrumbs would lead Addie straight to the proof she needed. I couldn’t even collect them without my signal laying a fresh trail.

Even without proof, an accusation would be enough for the Consort to look more closely at what I’d been up to. When they did, they’d find Simon, with his SRT and his Baroque events.

Simon, who needed me to save his mom’s life.

What’s the point if you can’t save people? Make the world better?

My future with the Walkers was unraveling faster than any cleaving. If the Consort was going to cast me out, I might as well use my last few Walks for good.

When I looked up and found myself standing across the street from Simon’s house, the choice was easy.

Iggy heard me coming before I could knock on the door, his big bass woofs rattling the windows. Simon’s shadow appeared, and then he was standing in front of me, one hand gripping Iggy’s collar, one hand braced on the doorframe. The clever things I’d imagined saying—the defenses I’d counted on for so long—flew out of my head.

He was backlit, the lamp glow keeping his face in darkness. I couldn’t tell if he was pleased or angry to see me shivering on the steps.

“I can’t promise,” I said, huddled in my coat. “And if it puts you in danger, I won’t do it. But I’ll try.”

There was a long, awful pause, a pivot swelling as he studied me.

He held out his hand.

I took it, and he pulled me into the warmth and the light, into him. The awful tightness in my chest loosened, finally, and I could breathe him in, soap and sunshine even at night.

“Come and meet my mom,” he said.

The front room was clearly for show, with furniture that looked too small for Simon’s height and sprawl. He led me through the narrow kitchen, with white cabinets and cheery, apple-green walls and a round table with three chairs. It opened up into a bright, cozy family room. The woman sitting on the couch, feet tucked under her, a red chenille throw on her lap, looked up expectantly. A book lay facedown on the table in front of her, a teacup at her elbow.

“You brought a friend home! Why didn’t you tell me?” Mrs. Lane said, and started to get up. Simon went to her side immediately, but she waved him off.

She was taller than me, but not by much. He must have gotten his height from his dad. A scarf covered her head, a few wisps of honey-blond hair poking out at the edges, but her eyes were the same dark, sparkling blue as her son’s—intelligent, lively, and right now, full of speculation.

“Mom, this is Del Sullivan.”

“It’s lovely to meet you, Del. I’m Amelia.”

“You too. I didn’t mean to interrupt.”

“You’re not. I was reading, and Simon is entertaining that monstrous dog.” Iggy nosed his way over to her, and she gave him an affectionate scratch around the ears. “Take her coat, Simon. Please, sit down.”

Iggy plopped down in front of her. “I was talking to our guest, you beast. Del, would you like tea?”

“No, thank you.” Simon slipped my coat off my shoulders, his fingertips grazing the nape of my neck. I wrinkled my nose at him—getting grabby in front of his mom was not the impression I wanted to make—but his face was a picture of innocence. He nudged me toward an overstuffed armchair in a red-and-white stripe, and I perched on the edge, ready to bolt.

“Simon says you’re working on a music project together?” she asked. “I hope he’s not making it too hard on you.”

“Hey,” he said, sprawling on the floor at my feet. “I’m not that bad.”

I saw Simon in her grin. “You absolutely are, and you know it.”

He hung his head in mock defeat. “I’m going to make it up to her. I’m going to teach her the finer points of a pick and roll.”

“I’m sure Del will find that tremendously useful,” she said. She shifted her attention to me. “In your career as a professional basketball player, of course.”

“It’s always been my dream,” I said, drawn in despite myself. The affection between them was so obvious, and they included me as if it was perfectly natural. A pang of envy ran through me.

He ran a hand along my calf. “Don’t tease, Delancey. I have other talents.”

I kicked him as discreetly as I could.

“He makes an excellent toasted cheese sandwich,” Amelia said, as if she was giving the matter great thought. “And his chicken soup has come a long way.”

Simon nodded gravely. “I’m amazing with a can opener.”

“Delancey,” Amelia mused over her teacup. “That’s a pretty name. Unusual.”

Traditional, for Walkers. “I was born in New York,” I said. “But my parents knew we were coming back here, so they named me after the subway stop near our apartment. I’m lucky we didn’t live near Flushing.”

“They named you after a train stop?” Simon said. “Wait. Addison? Montrose?”

“My family has a strange sense of humor,” I said weakly.

Simon raised his eyebrows. “Your family is strange, period.”

“All families are,” Amelia said, a hint of strain showing around her eyes. The teacup clinked as she set it down. “Chamomile makes me sleepy. I think I’ll turn in early, give you two some privacy.”

Simon clambered up. “You okay?”

“I’m fine,” she said. “It was wonderful to finally meet you, Del. Promise you’ll come back again.”

Iggy padded along beside her as she left. Simon watched, worry etched around his mouth and eyes.

Finally, she’d said. As if he’d mentioned me before today. Before he knew the truth.

“Is she okay?”

“Yeah. She gets tired pretty fast.”

“I shouldn’t have come,” I said, and he dropped onto the ottoman, one leg on either side of mine.

“I’m glad you did. So is she. Besides,” he said, sliding his hand around my neck and drawing me in for a brief kiss, “she’s heard a lot about you.”

“You didn’t tell her about . . .”

“How could I explain it? And after you said it was impossible, there wasn’t any point.” He fit our hands together, his fingers twining with mine. “You said bringing back a treatment could do more harm than good. What changed?”

“Me,” I said. “If we do this, I have ground rules.”

He leaned back. “Never thought I’d hear you say that.”

Neither had I. “One, if it puts the Key World in danger, we stop. Two, if it puts either of you in danger, we stop.”

His jaw tightened, but he nodded.

“Three, your mom has to be sure.”

“I’m sure,” he said quickly.

“Not you. Her. I can’t guarantee that I’ll find a treatment, but if I do, you have to tell her the risks, and she has to sign off on it. I won’t use my Walking to take away her choices.”

He bent his head, his words muffled. “Fine. Once we find a cure—if we do—how do we get it back here?”

“I don’t know yet. It’s fine to bring things from the Key World to Echoes. When I Walk, I leave stars behind. They’re so small, hardly anyone notices them—we call them breadcrumbs, because we can use them to find our way home if we get lost.”

“Does that happen?”

“My grandmother,” I said after a minute. “A few months before I was born, she went out for a Walk, and she never came back. That’s when Monty started to lose it. It’s why we left New York—to take care of him.”

He brushed his lips over the back of my hand. “I didn’t know it was dangerous.”

“We navigate by listening to the differences in frequencies. That’s why we’ve got such good hearing, but the sound wears us down after a while. It’s not bad in limited amounts, but if you stay too long, it starts to scramble your brain. The longer you stay, the worse it gets. That’s why we usually go with a partner.”

“Like Eliot.”

Not anymore. “My grandmother went out alone. People do it, especially on short Walks. But she disappeared.”

“You don’t think she left on purpose?” He sounded skeptical.

“No. We think she got disoriented, and the farther she Walked, the more lost she got. The Consort—our leaders—sent people to look for her. My grandfather is still looking. But she’s gone. There’s no tracking someone through the multiverse after so much time.”

He squeezed my leg, the contact scorching even through my jeans. “At least she didn’t bail on you guys.”

Unlike his dad. “How long ago did he leave?”

He grimaced. “I was three days old. I have it on good authority that I was a delightful infant, so I guess he wasn’t cut out for fatherhood.”

“I’m sure you were adorable,” I said.

“I really was.”

Something buzzed at the back of my mind, a warning prickle, and I tried to focus on it. But Simon kissed me again, and it slipped away like water through cupped hands.

“You said medicine from an Echo might hurt her. How are we going to get around that?” he asked.

“I think the trick is not to bring the drugs themselves. That way we’re not introducing a new frequency to the Key World. I could track down the formula, and then we could. . . .” I trailed off. We could what? Open an illegal pharmaceutical lab? Find a chem major at the university who was willing to experiment? And what if it wasn’t medicine, but a surgery? What if I’d given Simon a second round of false hope? “I’ll find a way.”

“We’ll find a way,” he said.

“You can’t go with me,” I reminded him. “And if there’s a problem with the frequencies overlapping, I’m calling it off. I can’t put you or the Key World in danger, even if it means you hate me for the rest of my life.”

“You’re risking your own life to help her,” he said. “How could I possibly hate you?”

I shrugged. Easy for him to say that when he didn’t know what I’d done. “Just so we’re clear.”

“Crystal,” he said, and kissed me again, pulling me onto his lap, one hand sliding along my back, his lips tracing my ear. “Take me with you.”

“You tried, remember?” I sat up, braced my hands against the wall of his chest. “You couldn’t follow me through.”

“You could help me,” he said. “Like a guide. Come on, Del. Pretend I’m a breadcrumb.”

“I’m not a guide,” I said, tugging the hem of my shirt back into place. “And you’re not a breadcrumb.”

Simon wasn’t the way home. He was home.

“What’s the worst that could happen? I get left in the equipment closet again?”

“I don’t know what the worst is. I don’t know how the frequency would affect you. The equipment closet was a terrible location, by the way.”

“It lacked ambiance, but I enjoyed it.” His hand inched along my thigh.

I smacked him. “For Walking. It’s easier when the pivots are established.”

“So we’ll find one that’s established.”

“You passed a bunch of them the other night at the Depot, and you never noticed. It won’t work.” But part of me wondered. I’d learned to Walk by holding on to Monty’s hand and letting him lead me through Echoes. My dad’s team had carried him back unconscious.

“One try. If I can’t cross, I won’t bug you again. If I can, and there’s a problem, we’ll come back right away.” His touch made me light-headed. “Let’s go break some rules.”

Twenty minutes later we were sitting in the Depot’s half-full parking lot, staring at the train crash’s memorial.

“How does it work?” he asked in a low voice.

“Why are you whispering?”

“I don’t know. Felt like a whispering kind of moment. Clandestine.”

“Everything with you is clandestine,” I said.

“It doesn’t need to be. You want to announce to the school we’re together, I’m more than fine with it.”

“One thing at a time, okay?” Bree’s reaction didn’t worry me nearly as much as the Consort’s.

I climbed out, Eliot’s map in hand. The edges of pivot points caught on my coat, stronger than before. We needed a large, stable rift, one I could cross without much concentration. No sense making this more difficult than necessary.

“You have to hold on to me.” I checked the screen and headed for the far end of the parking lot. “Don’t let go, even for a second.”

“Got it.” He gave me a smile that tilted toward nervous, and took my hand in his.

“I can do this alone,” I told him, trying to give him an out. “You don’t need to come with.”

“Yeah, I do. It’s dangerous, right? Even for you?”

“It can be. But I am very, very good.”

His smile quirked up. “I’m sure you are.”

“Do you see the rift?”

The air around the pivot looked more dense, a sliver of night that the amber glow of the streetlamps couldn’t penetrate. I gestured, and his eyes locked on my hand.

“Nope. But I feel weird, like an electrical storm is coming.” He took my hand. “Go ahead, Del. I trust you.”

Not many people did—not even me. But belief is a powerful thing. In that moment I was trustworthy because he believed in me. Simon’s faith transformed me into the person he thought I was.

With Simon’s hand gripping mine, I felt my way through, the air oppressive and unyielding. I breathed out, slow and steady, my entire body attuning to the frequency, fixing the sound in my mind, pushing away thoughts of Simon, of the Consort, of anything except the world I was trying to reach.

My foot slid forward a few inches, the air resisting the entire way.

It had to be Simon. His frequency was locked into the Key World, holding us back.

When I looked over, his jaw was set in concentration. He’d never agree to quit.

I pressed on, inch by inch, and gradually my hand pushed into the other world, the resonance unpleasant but not painful. Foot, knee, elbow, shoulder, head, each a struggle.

Finally I was clear, except for my hand holding his. I willed the pivot to part, planted my feet, and tugged.

There was an awful, excruciating tension as the pivot ground along my wrist. It wouldn’t work. I’d lose him. Maybe I’d lost him already, and he’d disintegrated in the subatomic spaces between worlds. I swore under my breath, hauled as hard as I could, channeling my panic into action.

Like a cork from a bottle, Simon burst free. We went down in a tangle of arms and legs on the pavement.

“You’re here,” I said. “Oh, God, you’re really here. I thought—”

“It worked?” Wide-eyed, he took in the nearly deserted parking lot. We’d landed at the end of a row, at the base of a parking meter. “We did it? Holy crap, Del.”

I fought back tears of relief. We’d made it. Simon could Walk, and everything I’d ever been taught was wrong. I flopped back onto the ground, heedless of the gravel biting into me, and stared up at the sky, surprised the stars were lodged in their familiar constellations. My whole world tilted on a new axis. The stars should be different. Everything was different.

I listened carefully, gauging the pitch and stability, searching for any breaks that might hint at a problem, but the Echo sounded safe. How had the Consort been so wrong?

It wasn’t the first time. I thought back to the girl with the note cards, how I’d caused an Echo to transpose. How Monty had promised tuning could stabilize entire worlds. Maybe they weren’t wrong. Maybe the Consort wasn’t telling us everything.

Simon pulled me to my feet. “Are you okay? You said it can make you sick.”

“We’ve got a few hours before frequency poisoning kicks in. Hear the difference?”

He shook his head. “Still staticky, though. Where are we?”

The Depot was gone. In its place stood a boxy redbrick building, and the platform was lined with benches and warning signs. “New station. I bet the crash happened, but they didn’t move the location. But we can’t know for sure.”

Simon took it in, his eyes catching every detail. “It’s so real.”

“For the people in this world, it is.” I wondered if Simon would be visible, or go unnoticed, the way Walkers did.

“And my house is here? Can we check it out?”

“That’s not a good idea.” Echo objects weren’t supposed to come in contact with their Originals, and I assumed the principle applied regardless of where the meeting took place. The strain on the threads could be dangerous. “Maybe we should—”

“Do you think my mom is there?” He started off, not waiting for my response.

I chased after him. “Wait! You don’t know what you’ll find. It’s not a good idea to rush off.”

God, I sounded like Addie. All caution and common sense, while Simon viewed the world like he’d gone through the looking glass. My usual recklessness waned when he was at risk.

“Listen to me, okay? We can check out the house. But she’s not your mom. She’s your Echo’s mom. She might not even be home.”

“I have to see,” he told me. “You said we have to find a world where she’s cured. Maybe this one is it.”

“On the first try?” Unlikely. But he looked so hopeful, I matched my stride to his, and we went in search of his family.

“The town moved,” he said after a few blocks.

At home it was the north side of town that was busy, even at night. Restaurants and shops and lots of pedestrians, even when the weather was lousy. But here the business district had shifted south, toward the train station. We passed by Grundy’s, and he paused.

“Some things are the same,” I said, nodding at the familiar sign. “It’s hard to predict what changes from world to world.”

“But it’s only the Key World that matters?” He sounded troubled.

“Echoes matter,” I said softly. “But not in the same way. And not to all Walkers.”

Our words made smoky puffs in the cold air. “Is that why you don’t get attached? Because you can always find something similar. Or better.”

“Real is better,” I said quietly. My time with the Walkers was running out, but maybe I could forge a future with Simon in it. “It matters more.”

“Does it? This place feels real.”

Was Doughnut World Simon real? To me, yes. Was he enough?

I’d thought so, for a while. If I’d spent time with him over music and coffee and free-throw lessons, I might have gotten to know him beyond making out in a car. But the Simon standing in front of me was the one who’d told me about his family and asked about mine, who’d taught me how to shoot free throws and learned how to play the piano, however poorly. This was the Simon I wanted, not because of which world he belonged to, but because of who he was.

I pointed to his house. “There. Your mom’s Echo might be inside. She might be healthy. Would you rather have her, or the one back home?”

He eyed the door with a new wariness. “We have to see if she’s sick.”

“I’ll go in,” I said. Better not to risk an encounter between Simons. “Echoes don’t notice me unless I make an effort. What should I look for?”

“Check the cabinet to the right of the sink for medication. Or the calendar by the phone—look for doctor’s appointments.”

“Give me ten minutes,” I said.

“Can I—can I watch? Through the window?”

I wondered how he felt, witnessing a life that looked like his but would never be. Until now, all the people I cared about were Walkers, so I’d never had to watch their Echoes. Lonely, I thought. A different kind of loneliness than the one I’d known, but it still pinched at me.

“Of course.”

Worlds can form or fall apart in an instant.

We turned into the driveway, the door at the side of the house opened, and Simon’s Echo came out, the porch light glinting off his shaggy hair as he hefted a paper bag and took it to the recycling bin.

Behind me, my Simon froze. “That’s me.”

I shoved him into the hedge separating the cottage from its neighbor and dove after him. The branches rustled around us, and I prayed Echo Simon would blame the wind, that his tendency to notice me worked only when I was in plain sight.

There was a pause, then the sound of footsteps on gravel, diminishing as he walked back to the house. I sagged in relief.

And then I heard a sharp whistle, a metallic jingle, and the delighted bark that could only be Iggy.

“Bad dog,” I muttered.

An instant later Iggy nosed through the shrubbery, and my hand was covered in enthusiastic slobber.

“You can come out now,” Echo Simon called.

Simon grabbed for my wrist, but I shook him off.

“Stay here. Do not come out, no matter what happens,” I whispered, and stepped into view, my hair snagging in the branches. “Call off your dog.”

“Tell me why you’re trespassing,” Echo Simon replied. He shoved inky-black hair out of his eyes and peered at me. “You’re that girl. From school.”

“I’m that girl,” I said, forcing myself not to look at the shrubbery, where Iggy was still barking.

“Iggy, come,” he said, but the dog ignored him. “Who else is back there?”

“Nobody.” I widened my eyes and gave him my best smile. “I swear.”

He smirked. “You’re cute, I’ll give you that. But I’ll take the dog’s word over yours.”

I studied him, trying to figure out who this Simon was. Rail thin, lip ring, alt-metal-band T-shirt, and a look in his eyes that suggested he had at least a few of the real Simon’s memories.

He grabbed my arm and I yelped. Iggy’s barks turned frantic.

“Let go of me!” I tried to yank away, but he held fast.

“Last chance,” Echo Simon called as I struggled against him. “The dog might look goofy, but he’ll attack if I tell him to.”

“I doubt it,” the real Simon said, stepping onto the driveway, rubbing the top of Iggy’s head. “Sit, boy.”

Echo Simon dropped my arm. The dog looked between the two of them and whined in confusion.

“Oh, hell,” I said, as the world cracked open.

“What the fuck is this?” said Echo Simon, staring at the Key World version of himself. “Some kind of joke?”

“It’s bad,” I said, grabbing Original Simon’s hand. “Very, very bad.”

Around the three of us a tear was forming—not the usual pivot but a gaping slash. Iggy turned in fretful circles, but neither boy seemed to notice it.

The dissonance pouring out of the rift was so strong I nearly dropped to my knees. “Time to go,” I said through clenched teeth.

“What about my mom?” asked Original Simon.

“Mom?” said the Echo, looking poleaxed. “What about her?”

“We have to leave,” I said, as the rip grew. Around us the world started to flicker and dim, the first stirrings of a cleaving. “Now.”

“Is she sick?” Simon asked. “Did the chemo work? Or the surgery?”

Echo Simon shook his head, eyes somber. The rusting Toyota changed to a Volkswagen and back in a blink.

They looked at each other, two versions of the boy I’d fallen for, carrying a grief so big it crossed worlds. “Simon,” I said, and they turned in unison. “My Simon. You can’t be here.”

I stumbled into him, the world wavering as the breach widened.

“What’s wrong with her?” asked Echo Simon.

“Frequency,” I gasped, as Original Simon slid an arm around my waist, keeping me upright. “Go back.”

“To the Depot?”

I nodded. We needed distance. The crack hadn’t formed until the Simons had been in close proximity. If we could get away, it might slow down; if we left, it might reverse. Most importantly, I had to keep Simon safe.

“Take my car,” said Echo Simon.

“No!” The Toyota was cycling through different vehicles. If we were in it, we might get sent to another frequency and never find our way back. “Walk.”

Original Simon shook his head. “Run,” he said, and we took off as the world around his Echo continued to crumble.

I was right about the proximity. The farther away we got from Echo Simon, the more stable I felt. Behind us the erratic pulse of the tear slowed and steadied, a heartbeat returning to normal. The world took on substance and color. But Simon urged me along, not bothering to waste air or concentration on speech. When we reached the train station, I skidded to a stop, trying to hear the Key World. Simon barely looked winded. Leaning against a light post, I wheezed, “Thanks.”

“For starting . . . whatever that was?” He waved angrily in the direction of his house. “I couldn’t hide. Not when he was—I was—hurting you.”

“You’d never hurt me, here or anywhere else. You got me out.”

I couldn’t concentrate. My mind was whirling, trying to understand what had happened, trying to grab hold of the frequency I needed. Panic left me too scattered. I couldn’t get us back on my own.

I dug in my bag for the necklace Monty had pressed into my hand. How had he known I’d need it tonight?

The pendant was a miniature tuning fork—three inches long, perfectly balanced, with the worn patina of something much loved. The chain puddled in my palm as I tilted it under the light and saw the name etched into the tines.

Rosemont Armstrong.

Monty had given me my grandmother’s pendant. Which meant she hadn’t taken it with her when she disappeared. I couldn’t think about it now, but I would. Soon.

“What’s that?” Simon asked.

“The way back,” I said, and struck it on the light post. The sound rang out, soft but true, and the Key World pivot fluttered in response. I grabbed Simon’s hand and brought us home.

CHAPTER FORTY-FOUR

Damage to the fabric of a world results in a weaker frequency, rendering the affected threads more prone to future vibrato fractums and other problems.

—Chapter Five, “Physics,”

Principles and Practices of Cleaving, Year Five

EITHER PRACTICE REALLY did make perfect, or desperation counted for more than I realized, but the return trip was easier on both of us.

Not that it was easy. My legs trembled, my lungs burned, and my head ached like a New Year’s Day hangover. Simon looked better—the benefit of being a jock, I guess.

We sat in the Jeep with the heater on full blast. It was filled with fast-food wrappers and dog toys. I never wanted to leave.

“Hell of an introduction,” he said. “Is it usually this crazy?”

I curled up against his side, listening for any hint of damage. “Usually it’s pretty calm.” Except for cleavings.

His hand moved gently over my hair, removing twigs and leaves. “Iggy recognized me.”

“My grandfather says animals are better at that kind of thing.”

He touched his lips to my forehead. “What happened back there? I couldn’t see it, but it felt bad.”

I had no idea. This was uncharted territory. Thinking out loud, I said, “It wasn’t a pivot. Those come from decisions. It wasn’t a cleaving, because you can’t stop a cleaving after it starts, and this stabilized once we left. This was like the fabric of the world couldn’t handle both of your frequencies at once, so it ripped, then wove back together when we left.”

Was it possible for threads to re-form?

I checked the map, but the pivot we’d come through shone like a miniature sun—strong and steady. “It’s a freak thing. We might never know.”

Eliot would. Addie, too. Neither one of them was going to help me now. Monty, but he wasn’t exactly a reliable source. I clutched my grandmother’s tuning fork. Why hadn’t she taken it with her on that last Walk? She could have found her way home.

I slipped the chain over my head. Monty had answers; I’d simply been asking the wrong questions.

“You can’t Walk anymore,” I said. “We can’t risk running into your Echo again.”

“And you can’t go alone.”

“I do it all the time.”

“Not anymore,” he said, and kissed me.

“You are not the boss of me,” I said a few minutes later. “But I appreciate the concern.”

“I nearly lost you,” he said, tracing the chain of my necklace. “What if—”

“Everything is a what-if. That’s why I love it.” I paused. “We’ll find your mom. A healthy version. It’ll take time, that’s all.”

Time I might not have if Addie blabbed to Lattimer.

It was as if Monty had a secret ability—an ability other than Walking—that told him to lie low when he was about to be grilled. I waited as late as I could the next morning, hoping he’d show up in the kitchen and I could ask him about my grandmother’s pendant, or the strange dual-Simon tear or anything else. But my mom caught sight of me first and ordered me out the door to school, where Simon greeted me with a slow, knee-buckling kiss.

The entire corridor went silent, then filled with a hurricane of whispers.

“What was that for?” I’d wanted people to see me, but this wasn’t quite what I’d had in mind.

“Everything. Nothing. For being you, mostly.”

“For helping with your mom.” My heart twisted the tiniest bit.

“For offering, sure. But this—” He gestured to the space I’d put between us. “This started before I told you about her. It started way before I knew what you could do.”

It had started when I went after his Echo. But my guilt kept me from saying so. “Walk me to orchestra?”

“Gladly.” Before I could stop him, he hooked his arm around my waist, casual and obvious.

We passed by the trophy case, and I looked over my repair from yesterday.

And then I stopped cold.

“What’s wrong?”

“The trophies,” I said, fear gathering in my stomach like a leaden ball. “They’re different.”

“What do you mean?” He let go of me. “Wait. This is a conference trophy, not State. And where’s my net?”

“It must have slid back,” I said. “That’s what I was fixing yesterday, when you caught me. It was another world merging with this one. You were on the JV squad, I think.”

“I’m not in the picture at all,” he said. “Is this because of last night?”

“It must be.” I thought back to the cottage. The one-car garage. “Your Echo house didn’t have a basketball hoop.”

He closed his eyes, like he was trying to picture it. “No, I guess not.”

The Echo we’d met didn’t look like a basketball player; piercings aside, he moved differently than Simon, slouching instead of striding.

“The world bled through. When I fixed the trophy inversion yesterday, the strings must have been left vulnerable, so when your frequencies met last night, the damage showed up here.” Simon looked utterly perplexed. “Part of last night’s Echo has overtaken the Key World. Your doppelgänger didn’t play basketball. In that reality, the basketball team had a different season last year. These are their trophies.”

“I remember winning,” he said. “I remember cutting down the net. Won’t other people notice too?”

“I don’t know. This is advanced stuff. College level.” The pitiful little trophy didn’t move, which meant the inversion had taken root. “I need to Walk through and fix it.”

“For a trophy? No way.”

“It’s an inversion,” I said. “It will keep spreading until I fix it.”

“What if you don’t come back?” His fingers hooked in the pockets of my jeans, drew me closer. “Don’t go.”

“I’ll come home,” I said, and fished the pendant out from beneath my shirt. “I’m a Walker. This is what we do.”

“But . . .”

I skimmed my fingers along the glass, feeling the traces of the bad frequency blending with the Key World. The Consort would find this, I realized. With so many teams scrutinizing the area, nothing would draw their attention faster.

“Quit arguing,” I said. “Go to class. I don’t want you near the pivot when I go through.”

“Del—”

I brushed my lips over his cheek, like it was no big deal. “I’ll see you soon.”

He went, walking backward, his eyes on me the whole way.

I ducked into the girls’ bathroom, hid until first period had started and the commons had emptied out. There was no telling how quickly my mom or one of the other navigators would pick up on the inversion. I needed to move fast.

My hands shook as I found the frequency from last night and felt my way along it.

When I landed on the other side, the dissonance slammed into me like a hammer to the skull. The world swam in front of my eyes, the lights blurring. I planted my free hand on the wall to steady myself.

The fabric of the world was densely woven, nearly impossible to penetrate. I ran my hands lightly over the quivering material. No wonder the inversion was so stubborn—the problem strings were wound so tightly around the others, I couldn’t unkink them enough to restore the proper pitch.

I had no idea how much time had passed while I worked. Nausea washed over me in a greasy wave, and I took careful breaths. Nimble fingers, open mind, help to seek what you would find. There. I isolated the first strand, vibrating wildly out of tune.

It was the opening I needed. The more threads I fixed, the easier it was to repair others, the damage as pervasive as a choking vine. The vertigo was overtaking me, and I anchored myself with thoughts of Simon.

The last tangle of threads resolved itself, the resonance clear and stable, the inversion fixed.

Fixed too late.

My knees gave out, and I crumpled as the frequency poisoning kicked in. My grandmother’s pendant hung heavy around my neck, but my fingers were too cramped and numb to reach it. Is this how she’d felt, when she’d been lost? Would Simon miss me the way Monty missed her? The world tilted around me, going dark at the edges and narrowing rapidly.

Someone grabbed me by the shoulders, and a face appeared above mine, dear and familiar. Eliot.

The tunnel closed.

CHAPTER FORTY-FIVE

SOMETIMES THE MOST welcome sights are the most unexpected.

I woke up on the floor of a supply closet, burning with fever and teeth chattering.

“Bathroom,” I said, trying to curl up on my side. “I’m going to be sick.”

“What’s she saying?” I heard Simon ask. “What language is that?”

“It’s frequency poisoning,” Eliot said. “Her cerebral cortex is scrambled.”

“Sick,” I said, my tongue thick and clumsy. “I need to throw up.”

“Get her a Coke,” Eliot ordered, prying the tuning fork from my hand.

The chime of the pendant sank inside me, tamping down on the nausea. “You came for me?”

“Don’t try to talk,” he said, and tapped it again.

“The inversion. Is it gone?” My whole body shuddered, and someone shoved a sweatshirt under my head.

“She’s not making any sense,” Simon said, his voice rough.

I felt Eliot prop me up and heard the crack-hiss of a can being opened. The syrupy taste of Coke filled my mouth. “Swallow,” he ordered. The sugar hit my system and my muscles eased.

“Someone’s going to come by any minute,” Simon told him. “Can we move her?”

“Better now,” I slurred. A little of the tension went out of Eliot’s body.

“You’re better,” he agreed. “Welcome back.”

“The hell she is,” Simon growled. “Del? Can you hear me?”

I struggled to sit up, the cement floor cold and uncomfortable. “I have perfect hearing.”

“Not anymore,” Eliot said grimly, brushing sweaty strands of hair from my face. “And he’s right. We need to get you out of here.”

“Wait. Did it work? Are the trophies . . . ?”

“Screw the trophies,” said Simon. “I’m taking you home.”

Eliot touched my cheek. “It worked. Barely.”

“I’m bringing the car around,” Simon said. “Stay put.”

I drifted off. When I came to again, I asked Eliot, “Did you see me on the map?”

He made a face that was almost—but not quite—a smile. “Your boyfriend pulled me out of orchestra. He thought you were acting crazy.”

“Ah.”

“I told him that you’re reckless, not crazy.”

“Don’t forget selfish,” I said.

“That too.”

“What did he say?”

Simon rejoined us. “I said he could help you or I could break his legs. I’m more than a pretty face.”

I drank deeply, feeling better with every second. “You are pretty, though.”

“Ruggedly handsome,” he said, and helped me to my feet. “Let’s go.”

There wasn’t a lot of talking on the ride home. I concentrated on not throwing up, and both boys were silent. I didn’t know what Simon was thinking, but the computer in Eliot’s brain was definitely working overtime.

No one was home—even Monty was gone—so the boys helped me upstairs. After they’d settled me on the bed, Simon turned slowly, taking in the stars scattered everywhere, the maps I’d drawn, the battered furniture, the collection of instruments around my music stand. He looked like I must, every time I Walk into a new world. “Breadcrumbs,” he said softly.

“I came home,” I pointed out. “Told you I would.”

Some emotion I couldn’t read crossed his face.

Eliot coughed.

“Can you give us a minute?” I said to Simon. He looked at Eliot, then me, and nodded.

“More pop would be good,” Eliot said. “Her blood sugar’s dropped off the charts.”

“Got it.” Simon disappeared down the stairs.

When he’d gone, Eliot paced the room. “You shouldn’t have gone in there alone.”

“Turns out I didn’t,” I said softly.

“I would have helped. Even if he hadn’t threatened to kneecap me. You know that, don’t you?”

I hadn’t. I’d assumed Eliot was as selfish as me, and my eyes filled. “I’m sorry. For everything. For being so stupid and horrible and scared. You are totally right to hate me.”

“I don’t hate you.” He sat down on the bed. “I’m angry. But we’re a team. Always have been . . .”

“. . . always will be.” I dashed a hand over my eyes. “I screwed up.”

“Yeah,” he said, and I knew from the way his voice caught we were talking about more than frequency poisoning. “He shouldn’t be able to Walk.”

I winced. “He told you?”

“I can’t work with limited information. And I can’t believe you told him about us.”

“He caught me. I couldn’t lie.” When he raised an eyebrow, calm and skeptical, I amended, “I didn’t want to lie. Speaking of which . . . I didn’t tell you the whole truth.”

“Shocker.” He sighed. “What now?”

“There’s something wrong with him. Really wrong, Eliot. He was one of the breaks in Park World. His Echoes have been seeing me ever since. I run into him constantly. Every inversion I’ve found involves him. It’s not just the SRT, or the Walking. It’s something bigger. I think he’s caught in the anomaly.”

“We have to tell the Consort,” he said. “They’ll handle it.”

“They’d handle it by making him disappear.” I grabbed his hand. “Addie knows I’ve been Walking to see him. She’s going to tell Lattimer as soon as she finds proof. I need to get him clear of the anomaly before she turns us in.”

He drew his hand away. “And you need my help.”

I’m good enough to use, but not enough to love. Even woozy and exhausted, I recognized the danger. “No. If you’re involved, they’ll punish you, too. I’ll take care of this.”

“Yeah. You’ve got things totally under control,” he deadpanned. He kissed my forehead, eyes troubled. “Rest up. I’ll be back later.”

“Eliot . . .”

He waved and jogged down the stairs. I heard him say something to Simon, their voices too low to make out, and I sagged back against the headboard.

“I hate sitting here,” I said when Simon came back in.

“Bummer for you,” he said, and handed me a bottle of root beer. “Drink up.”

When I’d finished, he set the bottle on the floor and stretched alongside me. I shifted until my head rested on his chest, directly above his heart.

“You know, this is not how I was planning to get into your bedroom.” He trailed his fingers up and down my arm.

“Sorry to disappoint you.”

“Not disappointed. Worried. Are you sure you’re okay?”

“Frequency poisoning wears off fast.” To begin with, at least. The next time would be worse. I nestled in closer to Simon and tried to sound nonchalant. “I’ll be fine by tomorrow morning.”

“Eliot said you’re supposed to stay put for another day or two.”

“Eliot worries.”

“Eliot is in love with you.” There was no censure in his voice, only calm certainty.

“I’m such an idiot.” I closed my eyes, let the beating of Simon’s pulse resonate through me. “How did you know?”

“Recognized the signs.”

“Oh.” My eyes flew open. I didn’t know what startled me more—what he seemed to be implying, or how much I wanted him to mean it.

The silence between us grew weighty and he laced his fingers with mine. “You can’t take off like that again.”

I twisted to look at him. “How else will we find a cure for your mom?”

“It won’t help us if your brain is fried,” he said. “I couldn’t understand you when you came back.”

“Side effect.”

“What about next time? Or the time after that? No more, Del.”

“Don’t tell me what to do,” I said sharply. “You’ve known about Walking for forty-eight hours. I’ve done it my whole life. This is my choice, not yours.”

“What about rule number three? My mom has to sign off on it? Does she get a say?”

“I meant the treatment itself. You can’t tell her about the Walkers. What would you say? ‘Hey, Mom, do you mind if my girlfriend goes into an alternate dimension to find a cure for your cancer? It’s kind of dangerous, and it might not work, but are you in?’ She’ll have you committed.”

“I was thinking I’d try for a little more subtlety.”

“We stick to the plan. I find the cure, we figure out how to make it work here, and then we loop her in.”

“She’s not going to go for it, Del. Trust me.” Tension radiated down his arm; his words were tinged with bitterness. “She wouldn’t even want you to look.”

“You’re angry with her,” I said softly. “She’s accepted it’s terminal, but you haven’t.”

His body angled away from me, and I squirmed until we were face-to-face.

“It doesn’t matter how far down you are in a game,” he said. “You play until you hear the buzzer. You give it everything.”

“Until you can’t,” I said. “What if she’s tired of fighting?”

“Then I fight for her. But that’s my job, not yours.”

“I won’t stop Walking,” I told him. “Not even for you. You might as well let me help.”

His eyes met mine and he gave the slightest nod.

“Good. Once I’m back on my feet, we’ll get started.”

Before we did, though, there was something I needed to stop.

CHAPTER FORTY-SIX

Every action we take is a choice. Some are deliberate, some are automatic, but each represents a decision between paths. Viewed in this light, even inaction is a choice, albeit a weak one.

—Chapter One, “Structure and Formation,”

Principles and Practices of Cleaving, Year Five

THE WORST THING about frequency poisoning is how long it takes you to recover. If you go out again too soon, your resistance is half what it should be. I wasn’t in fighting form, but I also didn’t want to put off what I had to do for a moment longer. Eliot told my parents I’d caught a flu bug going around school, which got me out of Addie-time—but it also kept me from seeing Simon. On Friday, stir-crazy and missing him, I headed back to school, despite Eliot’s protests.

I trudged through the day in a fog. Only Simon was clear, urging sugar on me at lunch and keeping Bree at bay during music. By ninth hour, I was so worn down that even Mrs. Gregory believed me when I asked for a pass to the nurse’s office with only ten minutes left in the period. “She’s probably high,” Bree whispered.

I ducked into the girls’ bathroom, found the pivot, and crossed to Doughnut World.

I’d asked this Simon about his schedule the last time I’d seen him. He was in Spanish now, and I moved through the hall on autopilot. The bell rang and the corridor filled with laughter and chatter and shouts, kids bursting free of the constraints of the day. Already the frequency was wearing on me, familiar and ominous. I wove around clusters of people and couples reunited, my hand wrapped around my pendant. Lingering here was not an option.

Finally I saw him.

And he saw me.

Shock. Relief. Heat. Anger. The expressions washed over Echo Simon’s face, warring with each other, and finally settled into something I hadn’t anticipated. Wariness.

Hatred would have been easier. Would have protected him better. Hope and fear mingled together this way only meant more damage.

“Hey,” I said, and gave a small wave.

“Where the hell have you been?”

“Can we go somewhere else? Talk?”

“So you can give me another lame excuse? Don’t bother.”

I wished I’d never returned, but he’d trusted me. I owed him the truth—or a version of it. I had seen what happened when people left without explanation, how badly it wounded the ones left behind. It tainted everything that had come before and twisted what came after. Simon’s father had done it; so had my grandmother. Their absence was as tangible as their presence. “I told you I’d come back.”

He slammed his locker shut and stalked toward the side door. “For how long? I can never find you, Del. You’re a goddamn ghost. It’s like you’re not even real.”

“I am.” So was he, despite everything I’d been taught. I rubbed at my arms, trying to ward off the encroaching frequency. “But I can’t come back again.”

“Won’t.” He pinned me with a cold, contemptuous look.

“Can’t,” I replied. “I don’t belong here. Every time I see you, I’m hiding. I have to stop.”

“Hiding from what?” He thawed slightly. “Are you in trouble?”

“I’m trying to fix it.” Emotion wouldn’t help me, but I couldn’t stop the ache in my chest. “I wanted to say good-bye. You deserve a real good-bye.”

Because he was real, every bit as much as my Simon. He deserved better than the moments I’d stolen.

“Don’t do this.” He shook his head, bewildered. “Whatever the problem is, whoever you’re hiding from, let me help you. I can protect you.”

He touched my cheek gently, like I might shatter. Maybe I would.

“From myself?” I pressed my fingers to my eyelids. “You wouldn’t believe how many people have tried.”

We always have a choice. It’s one of the first things Walkers learn. There is always a choice.

It turns out my teachers were wrong. The more you care, the fewer choices you have. If you care enough, sometimes there’s only one. A single, impossible way forward, and you have to take it. Because it’s the only way to live with yourself.

CHAPTER FORTY-SEVEN

I CAME BACK jittery and nauseous and exhausted. I didn’t know if it was from Walking too soon or leaving Simon. Not my Simon, I reminded myself as I sat in the commons and downed a can of Coke, hoping to ward off another bout of frequency poisoning.

I’d cleaved one Simon, flirted with countless others, and wounded another moments ago. But the Simon who mattered most was the one who knew me best, and he was here. I would fix whatever problem was affecting both him and the Key World, we’d find a way to help his mom, and then we could be happy, here, together.

No more Walking to find other Simons. Never again.

Never didn’t last nearly long enough.

The sound of running feet caught my attention. Poking my head around the corner, I spotted the school nurse dashing toward the gymnasium, medical bag in hand.

“—says he’s fine,” said one of the other basketball players as they ran. “Coach didn’t want to take any chances.”

I might have been failing trig, but I could do the math.

I followed them to the field house, clammy with fear.

Simon sat on the bench, barely visible behind the wall of teammates looming over him. The nurse shooed them away, brisk and cheerful as she pulled out her blood pressure cuff. “Let’s see what we have.”

He waved her off, looking haggard. “Put me back in, Coach. It was nothing.”

“That was not nothing,” the coach growled. “Looked like a damn seizure.”

“I pulled an all-nighter,” Simon replied. “I’m good.”

“The hell you are. We’ve got a game against Kennedy tomorrow. I can’t have you fainting like a thirteen-year-old-girl at a rock concert in the middle of a full-court press.”

I could see Simon’s flush of embarrassment from across the room.

“Plenty of fluids and a good night’s sleep should do the trick,” the nurse said. One of the other players brought out a duffel bag and set it near Simon’s feet.

“Go home, Lane,” barked the coach. “Get some rest.”

“I don’t need—” Simon started to protest, but he caught sight of me and straightened, the set of his shoulders combative. “Sure, Coach. I’ll be back tomorrow.”

“Damn straight,” the coach said, and blew his whistle. “The rest of you—this isn’t a tea party. Get moving!”

Simon’s eyes never left mine as he crossed the room—it was like he was freezing me in place, and the closer he got, the colder I felt.

“Car,” he said, hefting the duffel bag. We reached the Jeep without another word. When he was behind the wheel, he turned to me. “I saw you Walking.”

I didn’t bother denying it. “How much?”

He snorted. “Everything. This whole time, I thought they were dreams, and you were . . . what? Hooking up with me in other worlds? It wasn’t enough that I fell for you here? I wasn’t enough, so you had to go and mess around with my Echoes?”

“No! It wasn’t like that!”

“And then you dumped me? Were you thinking you’d break up with both of us, make the worlds match?” He sounded insulted. “You were cheating on me with me.”

“I wasn’t! I haven’t been back there since before our date. Before things changed with us.”

“Things changed with us a long time ago.”

My own anger flared up. “Did you ever wonder why? You said it took you too long to notice me, but did you ever ask yourself what changed?”

“The project,” he said. “Powell put us on the project. And that night . . .”

“You dreamed about me. In the rain.”

“Outside Grundy’s. You gave me a star,” he said.

“You barely talked to me when Powell paired us up. You didn’t have an epiphany in the middle of music class. You noticed me because your Echo had kissed me the night before.”

He folded his arms. “You didn’t stop him.”

“Why would I? Nothing was ever going to happen between us. You’re the star of the basketball team, and I’m the freaky orchestra girl. So, yeah, when the guy I’ve had a crush on for years wants to kiss me, I go for it, even if he’s an Echo.”

“You went back,” he accused.

“You went out with Bree.”

“This is different. Don’t you dare tell me otherwise. You’ve been lying to me the whole time we’ve been together.”

“You didn’t know about the Walkers. How could I explain?”

“That’s bullshit, Del. You could have told me in the equipment room. That would have been the perfect time.”

“I’ve been a little busy,” I shot back. “You know, trying to save your mom’s life?”

“She’s not a bargaining chip,” he said fiercely. “You don’t get a pass on being honest with me because you said you’d help her. They’re totally separate.”

“The hell they are! You found out about the Walkers and asked me to help her on the same afternoon. When I said no, you took off. When I said yes, we were back on. If you want honesty, let’s start by admitting that the reason you’re with me is because I can help her.”

My breathing was ragged, my voice tight, and Simon drew back as if I’d slapped him.

“I was a dick,” he said. “When you told me about the Walkers, I didn’t think about whether it was dangerous, or how it would cost you. All I could think about was saving her. You risked your life for my mom, and that’s huge. I don’t even have words for how huge that is.”

I dug my fingernails into my palms, waiting for him to continue.

“But I’m with you—I was with you—because I was crazy about you. Walking had nothing to do with it. At least I thought it didn’t. Walking made a lie out of us, and that’s your fault.”

I bowed my head. “I didn’t want to lose you.”

“How’s that working out? Because from what I can tell, the me in that world isn’t exactly your biggest fan right now.” He grimaced. “Something else we’ve got in common.”

“Simon . . .” My head jerked up, but his gaze was fixed on the wheel.

“You were kissing me. You think my feelings were caused by him, but what triggered his feelings? Maybe I would have noticed you completely on my own. And now we’ll never know, because you don’t have any faith in me, and I sure as hell don’t have any in you.”

I grabbed his arm. “Hold on. What triggered him? He noticed me, and he shouldn’t have.”

“The low-self-esteem act is getting old,” he said, reaching across me to open the door, waiting for me to climb out. “You should go.”

I braced a hand against the doorframe. “Not self-esteem, you jackass. Physics. Walkers cast impressions in other worlds, but Echoes don’t remember them. He shouldn’t have noticed me, because we weren’t interacting. Here or there.”

“Maybe you stalked me in another world,” he said. “That seems to be your specialty.”

“I wasn’t stalking you. The only other time I’d run into you was at the park.” The truth came together like parts in a score, combining to voice what I’d missed. “You saw me at the park.”

“What park?”

“The world I cleaved,” I said, thinking of the duck pond, and balloons, and small changes that changed everything. “It was unstable, and you touched me.”

“It won’t happen again. I can’t stop you from coming after me in other worlds, but in this one? We are done.”

He drove off, leaving me alone in the parking lot.

Grieve later, I told myself. My thoughts felt tentative and light, like when I was picking a particularly sensitive lock, how pushing too hard would cause a tumbler to trip and I’d have to start over at the beginning. The park. I closed my eyes, losing myself in the memory of Simon’s hand curving around my thigh, how he’d steadied me and thrown me off balance with a single move.

The wrongness of his frequency, how strong the dissonance was every time we’d touched, in every Echo.

He’d noticed me in Park World because something was wrong with its frequency.

He’d noticed—and remembered—me in Doughnut World because there was something wrong with him.

He’d noticed me here, and the inversions started.

I’d had it backward. Park World Simon’s frequency hadn’t been wrong because the world was unstable. The world was unstable because there was something wrong with Simon. Because there was some sort of connection—bigger than SRT, bigger than a single frequency—between his Echoes. The more I interacted with them, the greater the transference. The stronger the frequencies. The more unstable his worlds became.

My parents had been looking for something in the Echo worlds that would cause so much instability, but the problem wasn’t an Echo.

The problem was Simon.

CHAPTER FORTY-EIGHT

I WALKED HOME on autopilot, my newfound realization—Simon was the anomaly, and I’d amplified the effects—turning the world around me ashen.

Every time I’d crossed realities and found him, whether it was Doughnut World or a lesson with Addie, I’d strengthened the connection between his Original and his Echoes. That’s why his SRT was so strong; it’s why the sky had torn when they’d met—their combined signal had been too much for one world to handle. It’s why the inversions I’d found were connected to him. It’s why he’d been caught in the Baroque events—because he’d created them.

He was the disease, not the symptom.

I was the carrier.

And I had to find a cure.

I didn’t notice Addie’s car until I nearly ran into it.

“Get in,” she snapped through the open window. I reached for the handle, stopped when I saw Eliot sitting in the passenger seat, expression somber.

I sighed as I slid into the backseat. “What did I do now?”

“You don’t know?” Addie asked, dour and disbelieving.

“It’s a really long list. Narrow it down for me.”

Eliot made a noise of warning, and I remembered that Addie’s search for proof could implicate him, too. If I wanted to help him out of this, the way he’d been helping me all along, I needed to draw her fire.

“For starters,” Addie said, “let’s talk about the Original you’re sleeping with.”

“I’m not sleeping with him! Why does everyone assume—I do have some self-control, you know.”

“You’ve demonstrated a breathtaking lack thus far,” she said. “Fine. You’re making out with him instead of going to class. He’s a problem, Del, and you have to end it.”

“Already done,” I said. “But there’s a bigger problem with Simon.”

“He’s the anomaly Mom and Dad have been looking for,” Addie said.

“How . . .”

Next to Addie, Eliot coughed.

I shoved his shoulder. “You told her?”

“She knew something was up.”

“The flu?” Addie said scornfully. “Hungover, I would have believed. Not the flu.”

Eliot twisted to face me. “I recorded a sample of Simon’s frequency while we were at your house. It sounds fine on the surface. Even my map didn’t pick up on it. But if you listen—really drill down and look at the individual oscillations, not the overall pattern—there’s a flaw. A minor correction in every cycle, like it wants to veer off-key but gets pulled back into line.”

“I have a D-minus in physics. What the hell does that mean?”

Addie spoke slowly, making each word distinct, like she was talking to a little kid. “He’s a pivot. His choices make stronger worlds. They’d be stable, if his frequency was right. But it’s not. So every time he creates a world, it’s not just off-key. It’s magnitudes off-key.”

Eliot took over. “It takes a while for the world to destabilize, because the flaw is so small. But when it finally goes bad, it goes bad fast.”

“Like Park World,” I said.

Eliot nodded. “I told you there was another reason.”

“And you told Addie first?” The betrayal stung. “Why?”

“You haven’t exactly been a model of restraint and clear thinking lately,” Addie said. “Leave him alone, Del. He was worried about you.”

I glared at Eliot, who shrugged. Apparently the days when I could boss him around were gone.

“What would do that to someone’s frequency? How do we fix it?” I asked.

“We tell Mom and Dad. They’ll tell the Consort, and the Consort will take care of it.”

They’d cleave him. “No Consort. We’ll handle it ourselves.”

We pulled up to the house, and Addie hit the brakes so hard that I almost slid off the seat. “This is why Eliot told me first. You’ve seen the damage he’s done. There’s no way we can fix it without help.”

“Then we ask for help,” I said, running through the possibilities in my head. Only one stood out. “But not from the Consort.”

CHAPTER FORTY-NINE

IT’S DEFINITELY A situation,” Monty said, once we were gathered around the kitchen table. He helped himself to another cookie. “You’re positive it’s the Lane boy? I met him, and he sounded fine.”

“The flaw in his frequency is so small, it’s impossible to detect without computer analysis. But it’s definitely there, and it’s allowing other frequencies to interfere with the Key World,” Eliot said. “Because he’s a natural pivot, he creates more Echoes than usual, and every one of them carries the flaw—so they’re all more likely to destabilize. The longer the Echo has been around, the longer it can withstand the flaw, but the newer branches are more vulnerable.”

Addie chimed in. “Every time he interacts with Del in an Echo world, the signal there boosts—and his Original remembers it. It’s like he goes into a trance here, and his entire consciousness is wherever he’s engaging with her,” Addie said.

“Just you, Delancey? No other Walkers?”

“I’m the only one he knows.”

He chewed thoughtfully. “You’re sure?”

“I’m not sure about anything,” I said. “Except that we have to help him, Grandpa. If the Consort gets hold of him, it’s the end of everything. His mom’s really sick, and he’s all she has.”

“And you’d miss him.”

I looked down at my coffee. I missed him already, but this was more important than my feelings.

“Look,” said Addie. “Not that Del’s heart growing three sizes isn’t great, but Simon is endangering the Key World. If we can’t figure out a way to stop the damage, we have to tell the Consort. That’s the rule. No exceptions.”

“I still don’t understand why his frequency is off,” Eliot said. “Or how he was able to Walk with Del.”

“The last one, I can explain,” Monty said, getting up from the table and reaching for his hat. “Let’s go find your boy, Del.”

Ten minutes later I was gathering my nerves on Simon’s doorstep while Addie, Eliot, and Monty watched from the car.

“I don’t want to fight again,” he said through the screen door.

“I’m not here to fight. The thing is—”

He spoke over me. “What you did was not okay.”

“I know.”

“I trusted you. I told you about my mom. I told you about my dad. You made me look like an idiot in front of the team. Every single truth you’ve told me, I had to drag out of you.”

I stared at the sunflower-strewn welcome mat.

“And I can’t blame you.”

My head snapped up, and he said wryly, “Well, maybe a little. But I didn’t give you much reason to trust me. You told me about the Walkers, and all I could think about was my mom. And considering how I acted at school—three years, and I looked right past you—I wouldn’t trust me either.”

“I do,” I whispered.

The faintest smile tugged at his mouth, and he put his hand against the screen. “That’s a good start.”

I matched my palm to his, the contact warm through the cool mesh.

“There’s something else you should know,” I said, and his smile faded. “Can we come in?”

“We?”

I pointed at Addie’s car, idling at the curb.

He sighed and pushed open the door. I signaled to Addie, then turned back to Simon. “I really am sorry about this.”

“Good to see you again, Simon.” Monty stuck out his hand as the others filed in.

Simon shook it, giving me a faintly disbelieving look, like he couldn’t believe we were going to waste time on social niceties.

“Where’s your mom?” I said, keeping my voice low.

“Resting. We’ll stay out here.”

I got the message. The back of the house, with its cheery kitchen and cozy family room, was off-limits for now. We still had ground to make up.

Addie spoke, brisk and businesslike. “There’s a problem with your frequency. A flaw that gets progressively worse with each iteration of your Echoes. We don’t know what’s causing it, but we do know the result: Some of the Echoes you appear in are destabilizing, and the damage is now spreading to the Key World.”

He looked at her blankly.

“Something in your frequency is off,” I translated. “And it’s causing problems across the multiverse. Big problems.”

Addie continued. “The damage is increasing to the point where the Consort will soon be able to track it back to you. If we can’t solve the problem before they do . . . Del thinks you and your mother could be in danger.”

He looked at me for confirmation. I swallowed hard and nodded, expecting him to get angry again. Instead he regarded Addie coolly. “Delivery like that, you should consider a career in oncology.”

She inclined her head. “Someone here has to think straight, and we all know it’s not going to be Del.”

I ignored her. “The Consort’s going to figure it out soon. We don’t have a ton of time, and we need your help.”

“I’m assuming you have a plan,” he said. Everyone was perched on the spindly furniture except for Simon, who stood at the door like he was about to throw us out again. Iggy padded in and made a beeline for me, resting his head on my knees.

“There’s always a plan,” said Monty. “They don’t usually work out like you’d expect.”

“You would know,” said Simon’s mom. We turned in unison as she walked in, clad in yoga pants and one of Simon’s old sweatshirts. “Hello, Montrose. I wondered if I’d see you again.”

“Hello, Amelia,” said Monty. “Wasn’t sure you’d want to.”

CHAPTER FIFTY

WHAT THE HELL?” I said, and Eliot elbowed me. “You two know each other?”

Monty dipped his head. “How long has it been?”

Amelia clung to Simon’s arm, her eyes red rimmed, the bright smile replaced by one more faded and resigned. And suddenly, I knew.

“Seventeen years,” I said. Every head in the room swiveled toward me.

“That’s my girl,” Monty murmured.

“I don’t understand,” Simon said.

“Seventeen years. That’s how long my grandmother’s been gone,” I said, edging closer to Simon, the way you would an animal about to bolt. “And so has your dad.”

“Del?” Eliot asked, putting it together. “Are you sure?”

“Sure about what?” Simon asked, his patience clearly at an end.

“Your dad’s a Walker.” My certainty grew as I spoke.

Simon shook his head. “My dad left.”

“Same as my grandmother. When’s your birthday?”

“January third.”

I looked at Addie, who shrugged. “Grandma disappeared on the ninth.”

“Not quite,” Monty corrected. “I needed to muddy the trail a bit. Give her a few days’ head start.”

“I’m a Walker?” Simon said.

“Half Walker,” Addie said. “Half Original. That’s why your signal’s so strong.”

“And why you were able to Walk with me,” I said. “You can’t find the pivots—you didn’t get your dad’s hearing—but you can move through them.”

Simon tensed, and I couldn’t tell if it was to attack or run. “You can’t ask for help like a normal person? You have to manipulate people? She’s lying,” he said to his mom. “Isn’t she?”

Amelia’s mouth trembled, and she ran her hands over his shoulders, smoothing imaginary creases from his T-shirt.

“Mom?”

“We were so careful not to leave a trail,” she said. “Rose delivered you here at home. We never put your father’s name on any records. We weren’t even legally married.” She touched the gold band on her ring finger. “He hid us away as best he could, to keep us safe until the Consort was finished. When he didn’t come back, it seemed safer to keep hiding.”

“The Consort discourages Walker-Original relationships because they weaken the genetic line,” Addie said. “They monitor the kids closely.”

Monty snorted. “If you believe that poppycock, Addison, I’ve got a bridge in Brooklyn to sell you. Those children aren’t monitored; they’re taken—if they’re lucky. And the child of a Free Walker—Gil Bradley’s son, no less—would have been a special prize.”

“The Free Walkers?” Eliot said. “Don’t they want to destroy the Key World, or something?”

“Hardly,” Monty replied. “They want to save the Echoes. Inversions aren’t the only things that can be stabilized. You can tune entire Echoes, rather than cleave. Protect all those lives.”

“Echoes aren’t alive,” Addie said. “There’s nothing there to save.”

“Who taught you that? The Consort, because it serves their purposes. They’d rather sacrifice the Echoes for their own gain, so they lie and tell you cleaving’s the only way.”

Eliot spoke. “You’re saying the Consort has been systematically deceiving Walkers for . . . how long? Twenty years? That’s impossible.”

“Nothing’s impossible,” Monty said morosely. “This has gone on much longer than twenty years. Generation after generation, we’ve drifted further from the truth, until we’ve forgotten what we were meant for. The Consort’s taken advantage, and the Free Walkers are working to stop them. They’re not madmen, or anarchists, or whatever other stories you’ve been spoon-fed.”

“I don’t care about Echoes,” Simon said in a voice hard as granite. “Whatever war you people are fighting has nothing to do with us.”

“But it does,” Amelia said, taking his hands in hers. “Your father was one of the Consort’s top navigators, but he’d been secretly organizing a group of Free Walkers to move against them. If they’d found out he had a child, they would have used you—used both of us—as leverage.”

“He bailed to protect us? You believe that? Mom, I know these people. They don’t care about anything except themselves and their stupid Key World.”

“I thought you’d be quicker, son,” said Monty. “Your father didn’t leave. He was taken by the Consort three days after you were born.”

“You’re working with them,” Eliot said to Monty. “You’re a Free Walker.”

“I did my part, back in the day.” Monty settled himself on the couch. “Once Rose was gone, there wasn’t much point to it.”

Addie tore her gaze from Simon and Amelia. “You and Grandma? Both of you?”

“She and Gil worked together. When he was caught, we knew he’d be interrogated.” Monty grimaced, and Amelia pressed her hand to her mouth. “Chances were good they’d find out about Rose, so she ran.”

“I don’t believe you,” said Addie. “If Grandma was a traitor, we would know. The Consort would have told us.”

“She wasn’t a traitor,” Monty snapped, anger distorting his features. “She fought for the good. You’ve met Randolph Lattimer. He’d cut out his tongue before he admitted that some of their top people revolted.”

Addie’s mouth opened and closed soundlessly.

“If you and Rose were both involved, why aren’t you in prison?” Eliot’s tone was cool and logical.

“Who says I’m not?” Monty said softly.

“That’s why Lattimer wanted us to keep an eye on you,” Addie said. “And why security’s so tight. They think Free Walkers are behind the anomaly. He was hoping you’d lead them to the Free Walkers.”

“Lattimer’s a fool. If I knew how to find them, I would have by now. Would have found Rose, too.”

“Why didn’t Grandma get in contact once the coast was clear?” I asked.

Monty sagged. “She got lost. She must have been terrified, and she ran so far and so fast, she couldn’t find her way home.” He clutched my sleeve. “We can find her now, Del.”

I covered his hand with mine. I didn’t want to tell him we’d be chasing a ghost. Nobody could survive in Echoes that long.

“Where’s my dad?” Simon broke in. “You said the Consort took him. Where?”

After a beat, Monty said, “An oubliette, no doubt. One of our prisons.”

Eliot cleared his throat apologetically. “This doesn’t change the fact Simon is a threat to the Key World.”

“You’re looking at it wrong,” said Monty. “He’s not weakening the Key World; he’s strengthening the Echoes. The boy’s signal is so strong, he even triggers Baroque events.”

“That’s exactly the problem,” Addie said. “There’s a flaw in his frequency making them unstable. If you start with ten bad Echoes, and you combine them, you end up with one really, really unstable Echo.”

“Easier to tune one world than ten,” Monty said. “We can use him. Take him into the worst of the Echoes, trigger a Baroque event, and tune the remaining branch. We do enough, and the problems with the Key World will disappear.”

“Hold on,” I said. “You want to take Simon into the Echoes?”

“Fastest way to do it,” he said. “And the Consort’s getting closer every day.”

“It’s a temporary fix,” Eliot warned. “The flaw in his frequency will keep causing problems. We need to know what’s causing it.”

“This buys us time to find out,” I replied.

Silence fell as we mulled it over. Amelia lowered herself into a chair, hands clasped in her lap.

Then Simon spoke, his voice razor edged. “Del? Kitchen?”

Amelia’s tea, steeping on the counter, had gone cold. A book of crossword puzzles lay next to it. The table was covered in Simon’s school papers, and I could picture the two of them joking around as he worked. Our arrival had stolen the moment from them, and I wondered if they would ever reclaim it.

“I had no idea about your dad, honestly,” I said, gripping the back of a chair. “It never even occurred to me.”

“My dad isn’t the problem.” He looked drained, face shadowed, and I wanted to put my arms around him. But tension crackled through him, like a downed power line, holding me at bay. “I keep thinking there’s something else. Some other bomb you’re going to drop.”

“I’ve told you everything I know. If there’s more, it’ll surprise us both.”

“It’s too much. My dad, and these problems with the Echoes, and . . . It’s too much.” He ran his hand over his head. “My dad. Jesus, Del. I can’t even think about him right now.”

I tucked my hands in my pockets, trying not to reach for him. “You don’t have to Walk. We’ll figure out a way to keep you out of it.”

“But it’s my frequency causing the problem. It’s my fault.” He hunched his shoulders. “The Consort. The people who steal kids and threw my dad in prison. They’re the ones in charge? And the Free Walkers fight them?”

“I guess. I thought they were a story, not real. Not organized, or powerful.”

“Maybe they wanted it that way,” he said. “If we don’t fix this, the Consort will find me. They’ll take me away from my mom, like they did to my dad. The best chance I have to stay here and have a normal life is to help you.”

“Last time you Walked, we almost died. It ripped the fabric of the multiverse. I don’t want to risk it.”

“More tears?” he asked.

“You. I don’t want to risk losing you.” Any more than I have already, I added silently.

“Because you care about me.” I nodded, and the tightness around his mouth eased. “But you don’t believe I care about you.”

“What you felt for me was rooted in your Echoes,” I said. Pictures of Simon hung from the fridge, and I studied them to keep from looking at him. They went back to grade school, a little boy clutching a basketball with undisguised glee and the same clear, direct gaze weighing on me now. “I’m not the choice you would have made on your own.”

“So, the Echoes’ feelings are real, but they aren’t. And I’m real, but my feelings aren’t. Works out pretty well for you.”

“Excuse me?” I wheeled around.

“If we crash and burn, regardless of which world you’re visiting, we weren’t real. And if it’s not real, it doesn’t hurt.”

It hurt plenty, so much that my throat tightened and my breath came shorter at the reminder. But I held my hands up in a gesture of surrender. “Can we back-burner the psychoanalysis for today? We’ve got bigger problems.”

“You’re scared.”

“The multiverse is about to start coming down around our ears. I’d be an idiot if I wasn’t scared.”

“You told the other me you’d been hiding. This is what you’ve been hiding from. Reality. There’s a million worlds for you to visit, but only one that counts, and you can’t control it and it terrifies you.”

He stalked toward me, and I edged away until my back hit the counter.

“You gave up on us pretty damn quick, didn’t you? Because it was real and you could have gotten hurt.”

“I am hurt,” I said, but it came out softer than I’d hoped.

“Me too,” he said. “It hurt to think of you with anyone else, even if it was me. You and I are real, Delancey Sullivan. I’m not letting you hide from that in this world or any other. So I’m coming with. You said my choices make worlds?”

I nodded, my breath coming too fast.

“Then I choose the world where you and I are together, and we solve this. Got it?”

He slid his hand around the nape of my neck, tipped my head back. “Got it,” I whispered, and he swallowed my words as we fell into the kiss.

“I would tell you to get a room,” Addie said from the direction of the doorway, “but you’re too young, and we don’t have the time.”

“Go away, Addie,” I said, eyes closed.

She clipped across the floor. “We need to get ready. And I’m sure Mrs. Lane would like to talk with her son. Which she cannot do while you’re mauling him.”

Simon pulled back, hands framing my face. “Tomorrow,” he said. “We’ll talk tomorrow.”

“Tomorrow,” Addie said, “we save the world.”

He kissed me again, lightly, and we went back to the living room, where Eliot was carefully inspecting the wallpaper. Monty waggled his eyebrows at me and turned to Simon’s mom.

“We’ll be off, then, Amelia. I’m sure we’ll see you again soon.”

She stood, fragile but determined. “I wouldn’t recommend waiting another seventeen years, Montrose.”

“No indeed,” he said, sadness in his smile.

“I’m sorry we brought this down on you,” I said to her, when everyone else had filed out. Simon stood behind me, hands on my waist.

“It was always a possibility,” she said. “Especially once Simon brought you home.”

“You knew who I was?”

“Not at first. But when you told me your name, and Simon mentioned Montrose, I knew it was coming.” She sounded miserable and resigned, and I wanted desperately to make her feel better. To make them both feel better.

“We’ll figure it out,” I said. “Monty’s really good. He must seem like he’s slipped a lot since you knew him, but—”

“I don’t think he’s slipped at all,” she said. “He’s exactly as he used to be.”

I relaxed slightly, and she pressed my hand between hers. “Please be careful. I know Walkers believe the Key World matters most, but Simon is my world. Take care of him.”

“I will. I promise.”

CHAPTER FIFTY-ONE

In rare instances, the destabilization of one branch can spread to others, creating a cascade effect and requiring swift action.

—Chapter Five, “Physics,”

Principles and Practices of Cleaving, Year Five

SATURDAY MORNING I woke early and found my mom in her office, door thrown wide. “Del,” she said, barely looking up as she shoved file folders and rolled-up maps into her bag. “You three are on your own today. I’d prefer it if you stayed out of the Echoes as much as possible.”

“Is there a problem?” I said, trying to sound curious instead of alarmed. Inside, my heart was pounding triple-time. “Some development with the anomaly?”

“We’re very close,” she said. “I’m hoping that the analysis we run today will pinpoint the source, but I need the Consort’s computers. And since your father’s not fully recovered, he’s going to coordinate the teams.” She slung her bag over her shoulder and headed for the kitchen. “We’re hoping this is the end, honey. Once we can get rid of the source, life will go back to the way it was.”

The source was Simon. Getting rid of him was not an option. Besides, after Monty’s bombshell last night, going back to the way things used to be had lost its appeal. The future was equally murky; how could I work for the Consort if Monty’s stories were true?

“Mom?” I asked. “What was Grandma like?”

“That’s an odd question,” she said. “Why do you ask?”

“Monty’s been talking about her a lot lately,” I said. “But you know how he gets. What was she really like?”

She poured coffee into a travel mug, dosed it with cream and sugar. Finally she said, “She was strong, I suppose. Practical, but not rigid. Not quite as . . . exuberant . . . as Monty. She loved your grandfather, and she loved what she did. She was absolutely devoted to her patients, to the teams under her care. They were like family to her. Sometimes I thought she cared more about them than she did our work. Or us.”

She snapped the lid on her mug. “I have to run. Be careful today.”

Before the car pulled away, I was texting Eliot and shaking Addie awake. We convened around the kitchen island, reviewing one last time.

“Simon spends the most time at school,” Addie said. “He’s already created a bunch of branches there, so they’re our best shot at triggering Baroque events. Grandpa, you’re going to help Simon. Del and I will handle the tunings. Eliot, you’re going to navigate. Everybody clear?”

“What about Lattimer?” I asked. “He always checks in on Saturday.”

Addie chewed on a fingernail. “He’ll be busy with Mom and Dad’s big meeting. As long as we’re home in the evening, he won’t find out.”

“You’re assuming we’ll finish this in one day,” Eliot said. “And that the Consort won’t be monitoring the area.”

“Maybe we shouldn’t bring Simon with,” I said. “When we were in music, he triggered a Baroque event without leaving the Key World. Why can’t we do it that way?”

“There’s no time,” Monty said. He pointed to the map in front of us. Addie and Eliot had circled several thickets of black lines, unstable but strong, that we would target today. “Lattimer’s coming. Your parents are close to finding Simon. The branches are growing more unstable by the day. The longer we wait, the greater the danger.”

“He makes worlds stronger,” Addie chimed in. “By bringing him into the Echoes, we can place the Baroque events exactly where we want them.”

She handed Monty a six-pack of pop and a package of chocolate bars, our defense against frequency poisoning. “Can you put these in the car, Grandpa?”

He took the bag and shuffled outside.

“It’s a Band-Aid, not a cure,” Eliot said, gathering up the maps and shoving them in his messenger bag. “There’s no way to change Simon’s frequency. He’s going to keep inverting the Key World. We should tell the Consort.”

“How can you say that after the horrible things they’ve done? They tortured Simon’s dad. They steal Walker-Original kids.” I folded my arms. “I don’t trust them.”

Eliot and Addie exchanged glances. “Del, there’s no proof any of those things happened. I’m not saying Monty’s lying . . .”

That’s exactly what he was saying.

“. . . but you know how easily he gets confused. A few weeks ago your mom was ready to put him in a home. Now he’s got this elaborate conspiracy theory. . . . It doesn’t add up.”

“I believe him,” I said. “And you do too, deep down, or you wouldn’t be here.”

“I’m here for you,” he said. “That’s it.”

“Even if there’s some truth to it,” Addie said, scattering the awkward silence with trademark efficiency, “the fact remains that the Key World trumps everything else. If it falls, the entire multiverse unravels.”

“I know.”

“Okay, then. If this doesn’t work, would you let the whole world crash to save your boyfriend?”

“This will work,” I said, heading out to the car. It had to work.

“I hope so,” Addie called after me. “Or I’ll turn him in myself.”

I threw my bag in the backseat of Addie’s car. Monty patted my arm reassuringly. “Don’t listen to her,” he murmured. “We’ll figure something out, you and I.”

I leaned my head against his shoulder, breathed in the scent of shaving soap. “Thanks, Grandpa.”

“You carry too much with you,” he said, his usual complaint. “A good Walker does more with less.”

“I like to be prepared.”

“You’re heading into infinity,” he said. “There’s no way to prepare for it. Did you bring the necklace, though?”

I fished the pendant out from beneath my shirt. “Why did she leave it behind?”

Monty reached out a gnarled finger and tapped it lightly, the high, clear tone carrying through the air. “You hold tight to it.”

Which was not an answer, and I was about to say so when Eliot and Addie appeared, Addie buttoning her coat, Eliot bobbling the rolled-up maps. I tucked the necklace away and tried not to worry about what they’d discussed when I was out of earshot.

We drove to the school in silence. The parking lot was empty except for Simon’s Jeep. He met us at the doors to the gym, freshly showered from practice.

“Everyone else is gone?” Addie asked.

“Yep. I hid in the equipment room till they left,” he said, and I blushed at the memory.

We moved through the field house in a loose knot, Eliot monitoring frequencies on his phone, Addie consulting the map we’d drawn up last night, Monty as nonchalant if he were out for a stroll. But his eyes were sharp and his hands were steady as he felt for vibrations in the air.

Simon hung back, his arm around my waist. “What are we looking for, exactly?”

“Listening,” I corrected. “For the pivot we need to go through.”

“I can’t hear it,” he said.

“You don’t need to. I’ll bring you across.”

“We have a problem,” called Eliot, his voice echoing through the room. He pointed to a banner at the top of the bleachers. As we watched, it flickered rapidly, popping in and out of sight.

I swore, and even Addie looked worried. “An inversion?”

“Two birds with one stone,” said Monty. “We bring Simon through to the inverted Echo, trigger the Baroque event, and tune the entire branch while you fix the inversion.”

Eliot tapped his screen. “You’d have to nail the timing. Tune it too early, and it won’t carry over into the final branch. Too late, and the inversion will have taken root permanently.”

“Fabulous,” Addie muttered. “Let’s get moving. The Consort’s monitoring for inversions, and this one’s big enough to grab their attention.”

“Why sports events?” Simon asked as we started up the bleachers. “First the trophy case, now the conference banners. Why is it always sports?”

“Sporting events form strong pivots. You form strong pivots. Put them together, and this is what you get,” Addie said.

Monty groaned from exertion. Simon and I helped him up the last few steps, and Eliot trailed behind, muttering about rates of oscillation and dampening effects.

When we reached the top, directly under the banner, I left Simon near Monty and placed my palm against the heavy felt.

“I can do it,” Addie said.

“I can do it faster.”

She looked like she was going to argue, but I closed my eyes and shut out everything except the frequency before me, isolating the bad string and following it back to its source, moving parallel to the wall. I was dimly aware of people fumbling behind me, but I kept pushing until I was through, gasping like I was coming up for air.

And nearly stepped into empty space. The bleachers were pushed in, and I bobbled on the ledge, fighting to keep my balance—only for Addie to knock me into the metal railing as she crossed. I tipped over empty space, my center of gravity too far off to compensate. My arms windmilled, trying to break my fall.

Addie caught my hand and hauled me upright. “Great start.”

“Your timing’s good, at least.” I clutched the railing so tightly my knuckles turned white.

An instant later Eliot appeared, and we steadied Simon and Monty as they came through, the five of us balancing on the top row.

Simon shuddered. “Am I ever going to get used to that?”

“Let’s hope you don’t have to,” Addie said. The pitch clashed with the buzzing of the giant fluorescent lights in their wire cage. I rubbed at my ears, feeling as if something were crawling inside them. On the floor below, the girls’ basketball team was practicing, oblivious to all of us.

“We’re invisible,” Simon said wonderingly.

“Welcome to my worlds,” I muttered. “Eliot, how long will the Baroque event take?”

He held his phone up to Simon, checking the readings. “Less time than I thought. It’s like we’re picking up momentum. I’m guessing three or four minutes, tops. Go ahead and isolate the inverted threads, Addie, but don’t tune them till you hear my signal. Be ready to move.”

“As long as there’s no pressure,” Addie said. I wondered if she was having second thoughts about helping me. But she simply closed her eyes and reached back into the inversion.

“How does it feel?” asked Eliot after a minute. Addie’s face was pale and strained, but there was a hint of triumph at the corner of her mouth.

“I’ve got the threads. Can I start?”

“Not yet. The Baroque event hasn’t progressed enough.”

Monty nudged Simon. “Move closer. It’ll speed things up.”

“Get over here,” Addie said, not bothering to sound polite. Simon brushed past me, and I went a little weak-kneed at the sensation, despite the seed of doubt unfurling within me. Something was off.

Simon stretched out a hand, inches above Addie’s, and the frequency ratcheted up. Monty and I both winced, clapping our hands over our ears.

“Go,” Eliot said, his voice wavering. “It’s moving fast. Ninety seconds, Addie.”

She bit down on her lower lip, brow creasing as her fingers made minute adjustments.

“Sixty seconds,” Eliot warned. Around us, the entire gym started to flicker, the Key World version alternating with this one, creating a strobe effect with the lights. Beads of sweat popped on Addie’s forehead.

“Thirty seconds.”

“Almost there . . . ,” Addie breathed. “Got it!”

The room trembled as if the molecules were rearranging themselves. The frequency crescendoed, rippling through us like a sonic boom, and Monty staggered into Simon. An instant later the pitch dropped back to almost normal, and our ears filled with the sounds of basketball practice—squeaking sneakers, basketballs on hardwood, the shouts of the coach. The banner was nowhere in sight, safely locked in the Key World.

“Knew you had it in you, Addie-girl,” Monty said.

“Time to go,” Eliot said. “Even if it’s tuned, we don’t want Simon boosting an Echo any more than necessary. The longer we stay, the stronger this place gets.”

One by one we edged through the pivot, easier the second time. I clung to Simon’s hand, pulling him through. Eliot dropped onto the bleachers, which were fully extended once again.

“We have to do that how many times?” he asked, looking haggard.

“As many as it takes,” I said, hauling him to his feet.

Simon touched my cheek. “Are you sure you can keep this up?”

“No problem,” I said.

An hour and a half later it was clear we had a very big problem indeed. We’d tuned the Baroque events according to our plan, but we’d also run across several inversions, each one bigger than the previous one.

“I don’t understand,” I said. We sat on the floor of the commons, Simon’s arm draped around my shoulder. I huddled against him, shaking. “Why isn’t it stabilizing?”

“We’re losing ground,” Addie said, massaging her temples. “The Baroque events are holding steady, but the inversions are increasing.”

“We’ve got to get ahead of it,” I said.

“We can’t,” Eliot said wearily. He took a bite of his chocolate bar. “The inversions are coming through faster than we tune the Baroque events. Look.”

He tossed me his phone and I scrolled through the map—the inversions showed up as pixilated blurs where there should be steady lights. Another burst of static took out the lower right corner of the screen as I watched. “How do we stop them?” I asked. “What’s causing it?”

“I don’t know,” he snapped. “I can’t think like this, with all these frequencies . . .”

“We need to tell the Consort,” Addie said. “They’re going to pick up on it anyway.”

“Not yet,” I pleaded.

“We need to start cleaving,” Eliot said. “It’s the only way.”

“Absolutely not,” said Monty, as a high-pitched whine filled the air. The room flickered around us.

“Time to go,” said Simon, hauling me up by the arm. “We can argue when we’re clear.”

We ran for the main office, and Monty dropped onto one of the wooden benches. When his breath evened out, he said, “We could cover more ground if we split up.”

“That is a terrible idea,” Eliot said. “In the entire history of movies, there’s never been a case where splitting up turned out well.”

“It’s a better idea than cleaving,” I said. “This isn’t a movie; it’s Simon’s life. We’re running out of time.”

“Del, we need to discuss this,” Addie said. “Review our options.”

“Discuss all you want. In the meantime, I’m going to stop the inversion.” I sprinted back down the hallway.

The noise streaming out of the commons hit me like a tidal wave. It was cycling rapidly, electric-blue carpet and white chairs changing to the familiar beige and maroon.

I plunged into the inversion before Simon or anyone else could stop me.

The dissonance was doubly strong on this side, furniture blurring, ground swaying. The damage was so widespread, I didn’t need to find a specific object—I closed my eyes and reached into the air, the frequency abrading my skin. Fighting the instinct to pull away, I dug in, and the fabric of the world peeled back. I began sifting through a million different strings, trying to find the ones out of tune.

The threads were as weightlessly strong as spider silk. Resilient, too. When I pushed, they pushed back, weaving together more densely as the world grew stronger. I imagined Simon on the other side of the pivot, trying to find a way through. He’d be furious when I got home.

If I got home.

Reckless, I thought, as the signal increased and threw me off-kilter, interrupting my search. That’s what they were always saying: Addie and Simon and Eliot, my parents, my teachers, the Consort. My recklessness had brought me this far, but now I needed to be more. I needed to be as good as I’d claimed, and that meant gathering up all my skills and all my wild jaunts through the multiverse to find the one strand that would calm this world down.

I breathed out, pictured Simon, breathed in, and reached through the threads one more time.

And found a piece of silk that twisted and kinked and sang in a key far different from the rest of them.

I grabbed it, traced the damage back to the snarl I’d been hunting, a cluster so large I needed both hands to span it. Bit by bit, I smoothed the strings, rocking them back and forth, coaxing and nudging until they chimed in harmony with the rest of the threads.

Done.

The instant I let go, the frequency roared around me, and I dropped to my knees, fumbling for the tuning fork at my neck. I tapped it once, twice, and followed the signal home.

Four pairs of hands grabbed at me. The room spun like a top winding down. “I did it?”

“Yeah, you did it. And you nearly gave me a heart attack.” Simon gathered me up in his arms. “Are you okay?”

“Never better,” I said, teeth clenched.

Wordlessly Eliot passed me a chocolate bar.

Addie’s face was bloodless, save for two splotches of red high on her cheeks. “What were you trying to prove?”

“We can split up, like Monty said. Cover more ground.”

“It’s too dangerous. Besides, without Simon, Eliot and I can’t trigger Baroque events.”

“We’ll still fix double the number of inversions. Hold off the Consort.” I stood, Simon’s arm tight around my waist. “Please, Addie. We can’t quit yet.”

Monty piped up. “If she’s willing to try, I’m willing to keep an eye on her.”

“It’s getting late,” said Addie, consulting her watch. “One hour, Del. If we haven’t turned this around by then, there’s no point in trying more.”

“Got it,” I said, and next to me, Simon and Monty made noises of agreement.

“Good luck,” Addie said, but Eliot scowled at Simon, and then he and Addie took off.

“What next?” Simon asked, looking from me to Monty.

“Next we start looking for another inversion. That way,” I said, and gestured toward the music wing.

Simon took my hand and we started moving, only to realize that Monty wasn’t following. He’d sat down on one of the couches in the now-stable commons, face slack and hands trembling.

“Grandpa? Are you sick?”

His eyes were a pale, watery blue. “We’re never going to get ahead of the inversions.”

“But you said . . .”

He tugged me down next to him. “Like calls to like. Every Echo he’s ever created carries the flaw. They’re being drawn here at the same time his flaw is weakening the Key World. It doesn’t matter how many we tune, they won’t stop coming. They’ll only get faster.”

“Then why did you want us to split up?”

“We need to take Simon away. Find another branch. Hide him from the Consort.” His voice dropped. “The minute they realize what he is, they’ll kill him.”

“You want me to run?” Simon sounded insulted. “Won’t I bring the inversions with me?”

“If we could find a world where we knew he never existed. A major branch, one without an Echo of him in it, would be more resistant to the inversions. It would buy us time.” Monty clutched at my arm. “Time’s the only thing we can’t choose. It runs like a river no matter how the world branches. But we can slow the damage if we draw him away. Let the Key World restore itself, repair the Echoes.”

It sounded crazy, but I couldn’t see another option. We needed time to fix the Key World, time to fix the flaw in Simon’s frequency. Time we didn’t have here, where reality was degrading.

“I don’t know any Echoes where he doesn’t exist, Grandpa.” I’d watched Simon for so long, I couldn’t even imagine a world without him.

“A place he’d never even been born,” Monty mused. “Your parents met at the train crash, didn’t they? Near the Depot.”

“If the crash never happened . . . ,” Simon said, understanding. He fished in his pocket for his keys. “I’ll drive.”

“Best we hurry,” Monty said, struggling to his feet. “The others will notice soon enough.”

I stopped cold. Addie would track us. “Someone has to stay behind and throw them off the trail.”

“Nonsense,” Monty replied. “We should all go. She won’t guess where we’ve gone.”

“If we vanish, she’ll turn us over to the Consort. We need you to stay here and talk her down. Stall her.”

“And we’ll go back for him later?” Monty frowned. “You know the risk, Del. It’s better if we stick together.”

“You said it yourself. There’s no time. Please, Grandpa.”

“Do you think you can handle Addie?” Simon asked.

Monty drew himself up, offended. “She’s just a girl. I’ve handled worse.”

“Then let’s go,” Simon said.

CHAPTER FIFTY-TWO

THE DEPOT WAS busy with the Saturday lunch crowd. Through the window I saw black-clad waitresses toting trays of lattes, oblivious to the disaster bearing down on us.

“Good date,” Simon said.

I smiled despite my nerves. “We’ll do it again soon.”

“I’m holding you to that.”

We climbed out of the Jeep. “Is the pivot at the memorial?”

“The Originals’ memorial marks where the train hit. The Walkers’ is where the engineer chose to maintain his speed instead of slowing down. If he’d applied the brakes a few minutes sooner, there would never have been a crash.”

We circled the building, crossed the grassy median between it and the tracks, and followed them a hundred yards, holding hands. I spotted the small cairn of white pebbles at the same time the pivot tugged at me.

“This is the spot,” I said, nudging a stray pebble with my toe.

“Your memorial is a pile of rocks?”

“It’s symbolic. We build it up each time we cross; the vibrations from the train knock it down. Entropy.”

I slid my arms around him, trying to fight off the panic crawling over me. “Ready?”

He nodded, jaw tight, eyes looking past me at a rent in the air he couldn’t see and was about to give himself over to.

“You shouldn’t get frequency poisoning. You’ll be safe.”

“How will you find me?” he asked.

“Wait at the school until I come back for you,” I said, taking his face in my hands, forcing him to meet my eyes. “I will come back.”

“I know.” He kissed me until I felt weightless. “The sooner we start, the sooner I see you again.”

I laced my fingers through his, memorizing the way we fit together, the feel of his skin against mine, the syncopation of our heartbeats. We’d crossed worlds together, but this time I would have to leave him behind. The thought of the Key World without him in it—for a day, an hour, a minute—felt as wrong as a world missing the color blue.

My phone trilled. “What?”

“Where are you?” Eliot hissed.

“About to cross a pivot,” I said, which was technically true. “Why are you whispering?”

“Addie’s on the phone with your mom. The Consort picked up on the inversions at the school. They’re sending a bunch of teams out to start cleaving. Your mom called to make sure we were staying home today like she asked.”

Cold gathered along my spine.

“We need to get out of here before they catch us,” Eliot said.

“Grab Monty and go,” I said. A train rocketed by, my hair whipping in the rush of air. When I could hear again, I added, “I’ll take care of Simon.”

Eliot was quiet for a long moment. “Del, for once in your life, think. This isn’t going to work. You can’t hide him forever.”

“I don’t need forever,” I said, and hung up.

Simon frowned. “Everything okay?”

“It will be,” I said, and reached for him.

Simon twitched when we came through, like Iggy shaking himself dry. The frequency here was flat but solid. A good sign.

We headed north, toward the school. The town had shifted toward the train station, storefronts jammed with high-end boutiques and gourmet restaurants. “What do I do while you’re gone?”

“Whatever you want,” I said. “People won’t notice you unless you touch them. You don’t have to worry about running into yourself.”

“Could I check on my mom? She might be healthy here.”

“Amelia Lane exists in this world,” I said. “But she’s not your mom. She never met your dad at the crash. She might not even live here anymore.”

She might not be alive at all.

“The Consort’s coming,” I said when we reached the front doors of the school. “I need to get home and come up with a cover story.”

“Is that why Eliot called? To warn you?”

I nodded, pressed my cheek against his chest. “I’ll come back tonight to give you an update. It’s good that your signal’s so strong—I’ll be able to track you without a problem. In the meantime—” I dug in my bag and found the package of origami papers. “Better start teaching yourself. Now that I know you can Walk, imagine the fun we’ll have.”

He smiled, but it twisted and disappeared before he could make it work. “You’ll take care of Iggy, right? And . . .”

“I won’t need to take care of Iggy,” I said, my throat aching. “Or anyone else. I won’t leave you here.”

“Del—just in case—”

I stopped his words with a final kiss, telling him everything I couldn’t bring myself to say, listening to everything I couldn’t bear to hear him speak.

“Tell me later,” I said.

“Tell her now,” Addie said, and I jerked away from Simon to see her standing at the edge of the parking lot, cold and white as marble. “You’re not coming back, Del. Ever.”

CHAPTER FIFTY-THREE

HOW DID YOU find us?”

I pushed Simon behind me as if I could shield him.

“You’re not hard to track, Del. He’s like a freaking siren.” She darted forward and wrenched me away. “Are you insane? Do you have any idea what you’re doing?”

“He was pulling the inversions into the Key World, so I moved him. How did you find us?”

“Eliot heard the train when he called and put it together. Moving Simon isn’t enough.”

“It will stabilize the Key World and get the Consort off his trail. That’s what matters.”

“His signal’s too strong,” Addie said. “When he was in the Key World, it drew the Echoes there. Now it’s drawing them here.”

“That’s good,” I said. “The inversions will stop.”

“All the frequencies,” she said, and took me by the shoulders, spinning me around. “Even the Key World’s. Look.”

A cast-iron replica of a steam engine stood at the front entrance of the school. As we watched, it shifted to a statue of George Washington. “I don’t understand.”

“I do,” Simon said, coming to stand next to me. “Did you know they changed the school mascot?”

“Did you know I don’t care?”

“Twenty years ago,” he said. “We used to be the Iron Horses. After the crash, they renamed the school.”

The sky tilted, the world going dim. “I don’t know what that means.”

“This world’s mascot is a train, not a president. But the Key World is being pulled here. Toward me.”

“We can’t win.” Addie’s eyes filled with pity. “The Consort was at the school when I left. They’re already cleaving the inversions. They’ll find this world, and they’ll cleave it.”

My stomach wrenched. All those Echoes, gone. All those Simons. All those lives we’d worked so hard to save, rippling away.

“Breathe,” Simon said, rubbing slow circles on my back. “Breathe, Del. In and out. Come on.”

“No. No. There’s got to be a way around this.” I dragged Addie to the edge of the sidewalk. “If we bring him back, the Consort will kill him.”

“We don’t know that for sure. They might fix him.”

I laughed. “They don’t want to fix things. It’s inefficient, remember? Why bother tuning an Echo when you can cleave it? Why bother saving a life when you can end it?”

“They’re preserving the Key World. You know this. It’s kid stuff. It’s what they’ve always taught us.”

“Exactly,” I said. “Did it ever cross your mind that they aren’t telling us the whole truth?” As fluid as water, as faceted as diamonds, as flawed as memory. What were the other facets? What was the Free Walkers’ truth? The Echoes’?

What was mine?

“Del, listen to me. You are the best Walker I’ve ever met. You can go anywhere. You can Walk to any world, have anything you want.” She gave me a gentle shake. “But you can’t have him.”

It was the easiest choice I’d ever made.

“Then I don’t want to be a Walker.”

“Do I get a say?” Simon asked. He rejoined us, tucking me against his side.

“Only if you can talk sense into her,” Addie said.

“You want to hand me over to the Consort,” he said, with the same shrewd look he used when sizing up the opposing team.

She met his eyes squarely. “You’re a nice guy. You care about Del, which is not easy, and you make her happy. If there was another way, I’d take it. But there’s not, and I won’t let the multiverse crumble because of one person, no matter who it is. I’m sorry.”

“Monty said this world was safe,” he pointed out.

“Monty was wrong,” I replied. Monty had been wrong about a lot of things lately.

“If they don’t get the inversions under control,” he said, “if the Key World keeps degrading . . . what happens to my mom?”

I didn’t say anything. He looked at Addie, who turned her hands skyward, helplessly.

“And if I don’t go back?”

“They’ll cleave this world,” Addie said. “Once they figure out the source is here, the easiest thing to do is unravel. That would stop your signal from affecting the Key World. Or any Echoes not connected to this one.”

“So either I hand myself over to the people who took my dad, or they cleave me.” He swallowed hard. “I gotta say, for people who deal in choices, the ones you’re giving me suck.”

“Choices,” I murmured. The plan came bright and fast as a lightning strike, a charge running through my body and stopping my lungs. Simon must have felt it too, because his eyebrows arched as he looked down at me.

I went up on tiptoe to kiss him, saying against his mouth, “Trust me?”

“Always,” he said.

I pressed closer to him, drawing out the kiss, savoring the taste of him, gaining strength from his signal and his steadiness.

Addie cleared her throat. “Del. We have to go.”

I turned toward her, wiping my eyes. “Five more minutes, Addie. Please. They’ll take him the minute we cross back. You know they will. This is my only chance to say good-bye.”

She hesitated, but Simon met her eyes and nodded once. Inches away, a pivot swelled into being.

“Privately,” I added.

“Fine.” Addie checked her watch. “I’m going to wait around that corner of the school. But in five minutes and one second, if you two aren’t walking toward that pivot, I will drag you both back there by your freaking hair.”

“You won’t have to,” I assured her.

CHAPTER FIFTY-FOUR

AS SOON AS Addie rounded the corner, I turned back to Simon. “Ready to go?”

“What?”

“We’ve got five minutes. Less, the longer we stand here talking.” I listened for the pivot he’d just created. “Kiss me again, in case she’s looking.”

“We can’t run.”

“If we keep moving, they might not be able to find you.”

“Running won’t help. You said so yourself. No matter where I go, the Key World will follow me. As long as I exist, everyone I love is in danger. My mom. Iggy. You.”

I leaned my forehead against his chest, feeling the tears start in earnest. “I’m not giving you up.”

“These Cleavers that everyone keeps talking about. What do they do?”

“The Echoes are connected by threads. The Cleavers cut the ones tying a specific Echo to the rest of the multiverse.”

“So they’re completely separate? No possibility of a crossover?”

“Cleaving unravels the entire fabric. Once the strings are cut, the Echo—and every Echo that came from it—disintegrates, from oldest to newest.”

“So it’s not instantaneous. You’d have time to get out.”

And then I understood.

“No,” I said, my voice cracking. “I’m not leaving you.”

He slid his hands through my hair and I closed my eyes, willing the tears back as his mouth came down on mine, more fierce and frantic than ever before. He tasted like salt and sunshine, and he smelled like the rain that was threatening to fall, and I knew I couldn’t let him go, not in a million worlds.

“Will it hurt?”

“I’m not doing it!” I tried to twine my arms around his neck, but he gripped my wrists, evading me.

“Will it hurt?”

“I don’t know! Echoes don’t feel anything, but you’re real. You’re mine.”

“You have to help me, Del. I can’t find the threads on my own.”

“Don’t do this,” I begged. “You’re the only person who has ever seen me, in my whole life. You see me, exactly as I am, and you still . . .”

“Love you,” he finished. “And this is how I save you. Save everyone.”

Except it wasn’t his job to save everyone. It was mine.

There was no getting around the truth this time. Simon was the heart of the anomaly, and my heart, and there was only one way to reconcile the two. To be both a Walker and myself.

“We stay together,” I said. “It’s a big world. It’ll take time to unravel. We keep moving, and we don’t give up.”

“You’ll be okay,” he said.

“So will you.”

“Show me the strings,” he said. “If I’m going to destroy the world, I’d like to at least know what it looks like.”

“They’re threads. Like a tapestry, but they don’t show a picture. They make a symphony. The most amazing symphony you’ve ever heard.”

“Then let me hear it,” he said. “Please. Before it goes bad.”

“And then we run,” I said. “Promise me.”

He kissed me, infinitely sweet, infinitely slow.

I traced his face with my fingertips, feeling the hint of stubble, the sharp line of his jaw, the shape of his mouth. I took his hands and kissed his palm, the way he’d once kissed mine.

Then I reached into the pivot beside him, feeling for the threads at the center of the world.

There. Just like I’d told him, a tapestry of strings and sound, strong and sturdy, off-key but not unpleasant, like hearing music from an unknown land.

His eyes met mine, sharp and dark and sorrowful. He slid his hand along my sleeve, over my hand, his fingers overlaying mine.

“It’s amazing,” he said, his face a mixture of wonderment and fear.

“It’s the fabric of the world. You’re touching infinity.”

“And I’m breaking it,” he said. “I’m sorry, Del.”

“Don’t apologize. We’re going to fix it.”

“No. We’re not.” Before I could ask what he meant, he wrenched the strings away, snapping them cleanly. The frequency screeched and skipped.

“I’m so sorry,” he repeated, and the world began to cleave.

CHAPTER FIFTY-FIVE

IT’S A BIG deal, the end of the world. There should be thunder and lightning and the parting of seas. It should look as momentous as it feels. As it is.

Around us, the few leaves clinging stubbornly to the trees turned muddy, the silvery bark going a dull gray. The sandy-orange brick of the school changed to beige, matching the mortar. Addie shot from the side of the building.

“Cleavers!” she shouted. “Time to go.”

“It wasn’t the Cleavers,” I said, feeling sick. “It was us.”

She skidded to a halt. “What? Why?”

“Because it was the only way,” said Simon. “Leave me here and the inversions stop.”

“Leave us here,” I corrected, unease creeping over me. “We have time to find a solution.”

“No! Del, this isn’t a solution. This will kill you. We have to go home. Now.”

“She’s right.” Simon brought my hands to his lips. “You promised you’d take care of my mom.”

“What?” I stared at him. “You promised we’d run!”

“I never promised.”

He hadn’t. He’d been so careful not to promise. “You are such a jerk.” I beat my fists against his chest. I wanted to scream the world down. To hate him for breaking my heart after he’d been the one to make me open it in the first place. “I’m not leaving you.”

“You’re not leaving. I’m telling you to go.” He pushed me toward Addie as the grass around the school turned silvery white. “Take her back.”

I shook her off and ran to him. “Don’t do this,” I pleaded. “Come with us.”

“Delancey Sullivan,” he murmured. “The girl who Walks between worlds. No wonder I kept falling for you. Can’t imagine a world where I wouldn’t.”

“I love you,” I said, crying now, finally. I didn’t think I’d ever stop.

“Glad to hear it,” he said, and stepped back as Addie caught me, her shouts lost in the ragged sounds of my sobs.

There was a ping, and a streak of silver raced across the ground between us, the inversion at the school splitting the Echo like a chasm. On his side of the flickering line, the world dimmed as if the sun had hidden behind clouds. On my side, the buildings swayed and slumped, the ground softening like tar. If I didn’t get back to the train station, I’d be trapped here—with Simon on the other side of that line, forever out of reach.

Simon made worlds stronger, Monty had said. Maybe his side would unravel more slowly. Maybe even slowly enough for me to get back and rescue him. I threw my backpack over the widening gap. If I was right, he’d need those supplies more than I did.

“Don’t get caught in the unraveling,” I shouted as he slung it over his shoulder. “Keep moving. I’ll find you.”

“Del!” Addie screamed over the white noise of the cleaving. “We have to get out!”

“Go!” he shouted.

I went, reality toppling around me.

CHAPTER FIFTY-SIX

MY FEET POUNDED along the ashen, sagging pavement, trying to outrun my grief. It followed behind me like a tangible thing, a weighty shadow blocking out rational thought. Addie urged me along, shocked into silence.

I reached the pivot, lungs on fire, muscles quivering. The white cairn on this side had scattered, stones tumbled across the grass. The power of entropy. I sank to my knees.

Grief caught me in its jaws and snapped me in two.

“Up,” Addie said. “You can lose it when we get home. Stay with me, Del.”

I listened for Simon’s frequency, trying to hear it one more time, but it was pointless. I’d never find him, I’d never be able to save him. The Key World was damaged, and it was all because of me.

Ignoring Addie’s pleas, I picked up a rock and threw it as hard as I could at the encroaching grayness. It flickered out of existence. I threw another. And another. And another, as if I could stop the unraveling somehow, as if my actions could freeze it in place. And then my fingers reached for another pebble, and brushed against something else. Smooth plastic instead of rough stone.

I wiped my eyes on my shirt and looked more closely at the inch-wide disk in my hand. Navy blue, the same as Simon’s eyes. Four holes in the middle, arranged in a square, just big enough for a needle to fit through.

My mom, handing my grandfather his sweater. “I don’t know how you manage to lose so many buttons.”

Monty, finger to his lips, winking at me.

“Breadcrumbs, Delancey. To mark the way home.”

It sat, humble and innocuous, in the palm of my hand, proof that Monty had been here. I combed through the remaining stones, and more buttons tumbled out. Tortoiseshell, polished wood, tarnished brass filled my hand, each one familiar, each one an indictment, each one bringing the truth closer, along with the cleaving.

Monty, who’d known Simon was half-Walker since the beginning.

Monty, who’d insisted we hide here.

Monty, who would do anything to find my grandmother.

“I don’t think he’s slipped at all.” Simon’s mom, eyes troubled. “He’s exactly as he used to be.”

“Simon needs to go into the Echoes. The plan won’t work without him.”

The crack of Addie’s palm against my cheek brought me back. “Quit throwing rocks,” she snapped. “We have to get out. Now.”

“Monty,” I said, showing her the buttons. “He came here a bunch of times.”

“Who cares? He won’t be coming back, and neither will we.” She took my hand and reached for the pivot.

But Monty hadn’t known we’d cleave it. He’d sent Simon to this specific world, knowing he’d amplify it. Believing we would come back. But for what?

What he always wanted. Rose.

She’d been a practical woman, my mom said. She and Monty would have had a plan. She must have fled here, a world that was sturdy enough to sustain her, dissonant enough to hide her tracks, with plenty of branches to hide in. She’d left behind her pendant because she’d never intended to return.

She wouldn’t have left a trail for the Consort to follow. But a sign. Something small that only Monty would have understood. Breadcrumbs.

Rose is my home.

Monty wasn’t trying to bring her back. He was trying to join her.

The plan had gone wrong, somehow. Maybe the Consort had been watching too closely; maybe Monty had been captured. The breadcrumbs faded and the trail was lost.

Why aren’t you in prison?

Who says I’m not?

For my grandfather, any world without Rose was a prison.

But Simon made worlds stronger. Once he was here, her breadcrumbs would have regained their strength, standing out like flares.

Monty must have thought he’d follow them right to her.

It was impossible. After so much time, it was practically impossible.

Nothing’s impossible, Delancey.

Especially if you were willing to risk the whole world.

I thought of Simon, his hair curling over his collar, eyes challenging me, hands drifting over my skin. I imagined him fading to gray, flickering with static. Simon, lost among the worlds.

My mother, shaking her head. “You and Monty are peas in a pod.”

She was more right than she’d realized.

CHAPTER FIFTY-SEVEN

I SHOVED A single button in my back pocket and followed Addie through the pivot, salt drying on my cheeks.

“Del!” Eliot raced toward us, Monty tottering behind him. “Are you okay?”

“Where’s Simon?” asked Monty, peering toward the pivot. “What did you do?”

“I cleaved it. Once it unravels, everything will be . . .” I swallowed down bile. “Finished.”

Addie wrapped her arms around me, but didn’t say anything.

“What do you mean, you cleaved it?” Monty said, face going gray. “The whole branch? With Simon in it?”

“What else could she have done?” Eliot turned to me, his voice kind and tentative. “The Consort has teams at the school, patching things back together.”

“Great.” My chest felt hollow, my limbs numb.

Monty sank down on a nearby bench, head in his hands.

“I’m calling Mom,” Addie said. I didn’t move.

“Lattimer’s on his way,” Eliot said, studying me as if I were an equation he couldn’t solve. “Tell me how to fix this, Del.”

“You can’t.”

“Lattimer doesn’t know about Simon,” Eliot said. “We told him you and Addie came here to tune inversions.”

“You lied to the Consort,” I said, barely interested. The numbness had spread through my whole body. “Why?”

“Because I have a theory to run by you.”

“Hold on.” I walked over to Monty. He looked as broken as I felt, a colorless lump in a worn cloth coat. Anger surged, breaking through my numbness, giving me momentum. I called to Eliot, “Can you grab me a Coke? I picked up more frequency poisoning.”

He glanced at Monty uneasily. “Back in a minute.”

I sat down next to my grandfather and said nothing. Pivots crowded around us, big and small, choice after choice overlapping, the air dense with possibility. All I had to do was pick one.

“I never thought you’d go through with it,” he said.

“Who says I did?” I pulled the button from my pocket and held it just out of his reach.

Monty stiffened.

“Eliot will be back soon, and Lattimer’s on his way,” I said, low and fast, urging him to believe me, not to question my story. “I cleaved the world partway. It’s still there. It’s not stable. It’s shifting, and it’s getting stronger, but I cut enough threads to stop the inversions. That’s why they think it’s gone.”

“Partway?” he said, the stirrings of hope clear in his voice. “I didn’t think that was possible.”

“Nothing’s impossible, right?” I pasted on the sly smile he used with me. “It should fool them for a few weeks. Long enough to track him and Grandma. We can do it, but we have to go now.”

“Now?” He blinked at me. “But . . .”

“Simon has to keep moving. The longer we wait, the harder he’ll be to find. Eliot’s coming,” I said, tugging at his sleeve.

His hand closed over mine, his eyes bright and sharp.

“Walk with me, Delancey.” The same words that had started off every Walk we’d taken since I was a child.

Eliot called out, but I waved him off as Monty and I strolled behind the Depot. He frowned, but instead of following us, he headed for Addie.

“There,” I said, gesturing to a tiny pivot hovering nearby. “I used another pivot to get out, like with the balloon.”

“That’s my girl.” Monty chuckled. “Always said you were my favorite.”

He stepped through the pivot and disappeared.

“You were mine,” I said to the shimmering air.

“It sounds different,” Monty said when I’d joined him. This world was nearly identical to ours, down to the cars in the parking lot. It couldn’t have been more than a few hours old—Monty should have caught on immediately. But desperation makes people believe in impossibilities. Desperation makes us foolish.

“That’s Simon,” I said. “He must be close.”

Monty hurried around to the front of the train station, more youthful than I’d seen him in years. Midway across the parking lot he stopped and peered around. “Are you sure we’re in the right place?”

“Dead sure.” I curled my fingers around the spindly threads of this Echo.

“I thought you said you’d cleaved it.” He turned. “Del?”

“I didn’t cleave anything,” I said. “Simon did. He made me show him the threads and he ripped them apart. And now he’s gone.”

Confusion clouded his features. “You said . . .”

“I lied.” My rage rose up, choking me. “I’ll assume you’re familiar with the concept. How long have you been planning this? Since I cleaved Park World? Since you heard Simon’s name? How long have you been using us?”

“You don’t understand,” he said, gaze locked on my shaking hand. “Rose is waiting for me.”

“How long?”

“After Gil was taken and Rose disappeared, the Consort came for me. A public trial would raise too many questions, but they had questions of their own. They took me into the Echoes and held me there till I was half-dead from frequency poisoning. Every day, for weeks. Told everyone we were searching for Rose, but they were making an example of me to any Free Walkers that heard the tale. Lattimer supervised it personally.”

“My God,” I breathed. Sympathy stirred, but my own loss crushed it.

“Finally they figured they’d made their point. But it was too late. I couldn’t hear Rose’s signal. That was the true torture, you know. They laughed as they watched me lose her.”

He dragged a hand over his face. “The Free Walkers had scattered. Amelia cut me off, thinking she’d protect Simon. There was nothing I could do. And then there was you, Del, bright as a button, bold as brass, my very best girl. You came home, and I knew you’d be my salvation.”

“Everything you taught me . . . all those tricks, all our Walks . . . were a scheme?”

“You were too good to waste on the Consort,” he said. “Only a few months younger than Gil’s son. Who better to watch over him?”

A flash of memory. “You picked Doughnut World. He went there every Thursday, and you threw me into his path. You called him to the office in Angry Dystopia World so I would find you both. You arranged our Walks so I’d run into him.”

It wasn’t the universe pushing us together; it was Monty.

“I figured if he saw you in Echoes, he’d trust you in this world. Despite the boots and attitude, Delancey, you’ve a soft heart. Once he asked you to help Amelia, everything fell into place, and then the inversions knocked it down again. I haven’t puzzled that one out quite yet.”

“You used me. You used both of us.”

“You would have done the same,” he wheedled. “You wanted to hide him away, even when you knew how dangerous he was. You would have damned the world to keep your love safe.”

“A Walker’s duty is to the Key World,” I said dully. “I couldn’t do it.”

“Ah, but you would have. It was Simon who cut the threads, wasn’t it? Not you.” He moved closer, hands up, his eyes never leaving the pivot. “It’s not too late. We can save them.”

“Stop lying!” I screamed. “Simon is gone. So is Rose. Forever.”

“Because you abandoned them!” he snarled, and caught himself. The momentary rage, replaced by sympathy and remorse. It was an act, and I wondered if his dementia was an act too.

Even fools are dangerous if they want something.

“I was going to stay. Save the Key World. Save Simon. We were going to run, but he stopped me.” My fingers twitched. “It’s a shame he’s not here now.”

“Delancey,” Monty said nervously. “Think.”

“I am. I’m thinking about when Simon asked me if it would hurt when he unraveled. I didn’t know. Would you like to find out?”

I heard the shimmering sound of the pivot, the Key World ringing out on the other side, beckoning me back to a place where Simon wasn’t. Where he was never going to be.

A hand came down on my shoulder. “Del, stop.”

“Addie?” I twisted to face her, but I wouldn’t let go of the threads.

Monty called out, “Addison, she’s not well. She overdid it, and the frequency poisoning’s back. We need to get her home.”

“I agree,” she said.

“No. You don’t know what he did,” I pleaded.

“He tried to use Simon to find Grandma.” At my startled look, she shrugged. “I told you Eliot put everything together. He’s worried about you. Come on.”

A three-man team came through the pivot, but I tightened my grip. “No,” I said. “He’s not leaving. It’s a tiny world. No one will care if I cleave it.”

“You’ll care,” she said.

“Simon’s gone.” Something inside me shattered, glass ground to dust.

“I know.” Gently she pried my fingers off the strings. Her nails, usually perfectly manicured, were bitten to the quick. “He did it to save you. Don’t waste it, Del.”

She pulled me back through the pivot, where Eliot and my parents waited. My mom clutched my dad’s arm, and they raced over as soon as we were clear. Lattimer followed behind, solemn but pleased.

All I could see was what wasn’t there.

I stood unmoving as my parents fussed over us, my mom smoothing my hair, my dad gathering me up in a bear hug. When he released me, Lattimer cleared his throat, and my parents stepped aside.

“You did well, Delancey,” Lattimer said. His hand dropped on my shoulder and I steeled myself not to flinch. “I knew you’d realize where your future should be.”

Behind me the pivot wavered as the team brought Monty back through. Lattimer’s face transformed, the proud smile turning predatory.

“Del! We can get them back! It’s not too late!” Monty shouted.

Out of the corner of my eye I saw the team drag Monty toward a black van, engine rumbling. He shouted again, “He’s more important than you know!”

He was everything. What could be more important than everything?

“There’s another way! People who can help us! Nothing’s done, Delancey! Nothing’s—”

The sound of the van’s door slamming cut off his cries, and then there was only silence.

CHAPTER FIFTY-EIGHT

IT TURNS OUT, the end of a world isn’t the end of the world. It only feels like it. Life pushes on, a vast unfurling that should be uplifting. Reassuring. An affirmation of the things we hold dearest.

I didn’t feel affirmed. I felt insignificant. Life pushed on, dragging me in its wake like a piece of driftwood. The music of the multiverse turned as distant and tuneless and monotonous as my days.

I walked, but not between worlds. Not anymore. I walked Iggy, long rambling trips that left us both shivering and exhausted. Easier to fall asleep that way, easier to ignore the dreams of paper stars in a gray sky and a bright-eyed boy beckoning me closer.

A week later I appeared before the Consort for the second time in as many months. My parents stood on either side of me, Addie near the door. Monty’s absence was palpable.

Councilwoman Crane folded her hands and spoke in the grave, formal cadence of the Consort. “Your suspension was to last until the end of the term, Delancey. We had hoped that the time would allow you to develop not only the techniques, but also the restraint required of licensed Walkers.” She peered over the top of her glasses, her smile dry as bones. “You can imagine our surprise when we learned of your involvement with the anomaly.”

I stared at the ballet flats I’d borrowed from Addie. The fluorescent lights made tiny, star-shaped reflections in the patent-leather toes.

Councilwoman Bolton spoke next, tapping the papers in front of her with one finger. “We have determined the anomaly was a collusion between Montrose Armstrong and the Free Walkers, created to destabilize the Key World. Now that the source has been cleaved, thanks to your actions, the multiverse is no longer in danger.”

I slanted a look at Addie, who kept her eyes fixed on Councilwoman Crane. She and Eliot had coordinated our stories before the Consort debriefed us, making sure to leave Amelia and Simon out of it. It had meant throwing Monty under the bus, but neither Addie nor Eliot seemed too guilt-ridden about it. I figured he’d gotten off easy.

I’d expected Lattimer to speak next, but he sat back, watchful and silent, as Crane took over again. “While your behavior was unconventional, it demonstrated your commitment to our highest principles: obedience, diligence, sacrifice. Your decision to keep Montrose Armstrong contained prevented him from taking refuge with other Walkers who are themselves fugitives.”

Other Walkers. There are people who can help us. Another one of Monty’s lies, and I dug my fingernails into my palms.

“Therefore, we are reinstating you, effective immediately. You shall resume your formal training, with credit given for your recent service.”

My mother exhaled, her relief audible. My father squeezed my elbow gently, but I didn’t respond. As quickly as they’d taken my future away, they handed it back.

I wasn’t sure I wanted it anymore, wasn’t sure where it led.

“Furthermore,” intoned Lattimer, “we would like to make a request.”

That got my attention.

“Your sister accelerated your training at my urging. It was clear that you had considerable talent, however undisciplined you might have been, and I’m pleased you rose to the challenge.”

He’d been testing me. Grooming me every bit as much as he’d groomed Addie, and I’d been too blind to see it. What else was I missing?

“As you’ve discovered, the Free Walkers do indeed pose a threat to our way of life. Our efforts to repair the Key World are ongoing. Considering the abilities you’ve demonstrated, and your knowledge of the situation, you’re . . . uniquely qualified to deal with the aftermath. Naturally, we would take this into account while determining your apprenticeship. Would you be willing to assist us, should we need you?”

A bribe. Help the Consort, and I would have my pick of assignments. I’d have more freedom than ever before.

What would I do with freedom? Walk to worlds where Simon wasn’t? I didn’t want his Echoes. I definitely didn’t want to watch his Echoes fade in front of me, like the man from the shoe store.

What I wanted was the truth. About the Consort and the Free Walkers, about my grandmother and the Echoes. Lattimer didn’t need my help; he had some other reason for recruiting me, and I wanted to know that, too. He’d never tell me outright, but he didn’t need to. Watch someone’s lies closely enough, and they’ll give away the truth.

“Happy to help,” I told him.

I almost meant it.

Later that night, Addie knocked on my doorframe. “Mom says you’re going to school tomorrow.”

“I’d like to see her make me,” I replied, and pulled the covers over my head.

She yanked them back again. “Stop moping.”

“There are a zillion worlds out there, Addie. Please go visit one of them. Or all of them.”

“I’m worried about you. Even Mrs. Lane is doing better than you are.”

“Mrs. Lane gets as many drugs as she wants,” I pointed out. “And she’s not doing better; she’s a wreck. I see her every day.” Simon had made me promise to take care of her, but we were taking care of each other.

“He wouldn’t want this for you, Del. He saved your life. The least you could do is get back to living.”

“Go to hell, Addie. Do not try to tell me what Simon would want. You barely knew him, and you didn’t like him. You sure as hell don’t speak for him.”

“Fine.” She hesitated at the door. “Monty’s sentencing was today. He pled insanity.”

My body clenched, waiting for her to continue. The Consort couldn’t let him go free. Not after what he’d done.

“They sent him to an oubliette. They said he was too dangerous to be allowed out.”

My muscles went lax. “I hope he rots there.”

“He freaked out. He was screaming for you. Started singing that song he made for you.” She nibbled a nail. “I’m sorry.”

I shrugged. “It’s not music, Addie, just noise. And I never have to hear it again.”

It was time to write my own song.

CHAPTER FIFTY-NINE

MY MOTHER WAS right. I did go to school the next day, worn down by nagging that began at sunrise and ended when Eliot escorted me off the porch.

“She’s going to text me every period to make sure you don’t cut,” he warned.

The sky was a faded blue, the sun a pale circle. I shoved my sunglasses farther up my nose and kept walking. “You can lie.”

“I could. But I won’t. You need to keep busy. You should come back to training, too. Shaw’s been asking about you.”

“Not ready,” I said.

He was silent for the rest of the trip, but there was a kindness to it. I was alone, but he wouldn’t let me be lonely.

All day I found myself looking for Simon. Not here, not here, not here, I whispered to myself. I couldn’t help searching. Couldn’t help hearing people who were wondering why Simon Lane had transferred out of state so suddenly, without even a word to his coach, despite the big tournament coming up.

Music was the worst. I stared at Simon’s empty chair, ignoring Bree’s glares and Ms. Powell’s lecture.

When the bell rang, Ms. Powell approached me. “Del? Can I speak with you privately?”

“I’ll wait outside,” Eliot said.

She gave him a thumbs-up and perched on the edge of my desk. “I’d like you to present your composition tomorrow, if you’re ready. The rest of the class completed their assignments while you were sick.”

“Yeah, I guess.” Simon and I had nearly finished the sixteen measures. I could knock out the rest that night, after I’d walked Iggy. It would give me something to do. I bent down to pick up my new backpack, much lighter than the one I’d left with Simon. I had no intention of Walking, so I didn’t bring my tools.

“The funniest thing happened yesterday,” Ms. Powell said, almost as an afterthought. “I could swear I saw Simon.”

“He moved,” I said when my heart started up again. “You probably saw someone who looked like him.”

“Maybe,” she said. “This guy did seem a little different. He needed a haircut. And had a metal bracelet around his wrist. It looked like a big shiny nail.”

A glint of silver in the glow of a streetlight. “A railroad spike.”

“I’d never thought of it that way, but . . . sure. Not the sort of thing you wear on the basketball court, is it?”

“Where did you say this was?” I choked out.

“I didn’t.” She smiled broadly, waved at one of the other students straggling out. “It was right outside this great doughnut shop downtown. Corner of Main and Evergreen? Do you know it?”

“I think so,” I said. There was no doughnut shop at Main and Evergreen. Not in the Key World.

“I like to visit there sometimes. Their Bavarian cream is out of this world.” She met my eyes. “He sounded great, Del. You know what I mean?”

Ms. Powell had seen Simon’s Echo. Yesterday. “You’re a Free Walker.”

“I’m a friend. Here. I’ve been meaning to return these to you.”

She held out her hand. Cupped in her palm was a mound of paper stars. My stars, the ones I’d dropped over the last few weeks, from the world I’d fled to after the first cleaving to the one I’d left in the library. I looked closer, but the dark green star I’d made in Doughnut World wasn’t among them.

“It’s an impressive body of work, Del. You’ve been through a lot. But it’s time to concentrate on where you want to go, instead of where you’ve been.”

Eliot stuck his head in. “We’re going to be late for class,” he called, as the bell rang and the three of us winced in unison.

“We’ll talk soon,” Ms. Powell said.

Not soon enough.

“If you’re hoping I’ll call you in sick for the rest of the day, guess again,” Addie said when she answered her cell.

“Why would Simon’s Echoes still be around?”

“You’re supposed to be in class. Let’s talk tonight.”

“Just answer the question. Why haven’t they unraveled?”

“They might be complex enough that they’ll stick around for a while. It’s not instantaneous, you know. Some terminal Echoes take years.”

“But they wouldn’t have a frequency, right? If his Echo was terminal, it would sound weird?”

“Yes. Did you go looking for one?” Her voice took on a sympathetic note. “I’m not sure that’s a good idea.”

“I didn’t. Let’s say he wasn’t terminal. Why else would his Echo be around?”

If Ms. Powell was a Free Walker, she would have known I couldn’t get back to Simon. Why would she tell me about his Echoes? And why had she waited so long to reveal herself to me?

Addie sighed. “Echoes won’t fade while the Original exists, but the Consort checked. The world Simon cleaved is no longer broadcasting a frequency. It’s completely unraveled.”

“Addie, this is important. Please, think really carefully. Is there any other reason why Simon’s Echoes wouldn’t be unraveling?”

“There is no other reason. He’s gone.”

But Simon’s Echo hadn’t faded, which meant his Original wasn’t gone.

He’d escaped the cleaving, and now he was lost in the Echoes.

And I was going to find him.

I’d promised, after all.

END THIRD MOVEMENT