A Midsummer's Equation

THIRTY-TWO

Kyohei’s eyes opened wider behind his goggles as he watched the little fish dart from behind the shadow of a rock. It was only the length of his fingertip, its scales a bright, shimmering blue. He reached out for it, but it was far too swift, so he settled for following its quick, jagged movements with his eyes until it disappeared behind another rock. He waited a while for the fish to come back out, but he was running out of air, and his snorkel was entirely submerged.

Kyohei returned to the surface, taking off his goggles and rubbing his face. Swimming on his back, he paddled with his legs back toward shore. He’d always been a good swimmer.

He switched to walking when he reached the shallows. The beach had been busy when he went in, but now only a few other swimmers remained. Most of the tents and beach umbrellas had been cleared away. Kyohei recovered his sandals from where he had thrown them and slipped them on before braving the hot sand above the waterline. His uncle Shigehiro was asleep on a beach chair beneath the lone remaining umbrella, a magazine spread open on his belly.

He called out to him, and his uncle’s eyes opened immediately.

“Hey there, Kyohei. Ready to head home?”

Kyohei nodded and pulled a bottle of water out of the cooler next to the beach chair. “Yeah, I’m pretty pooped. Hungry, too.”

“Right,” Shigehiro said, sitting up and checking his watch. “It’s after three already. Let’s get home. I think we have some watermelon in the fridge.”

“Cool,” Kyohei said. “Hey, guess what I saw? A blue fish. It was really bright, about this big.” He held his fingertips apart to indicate the size.

“Yeah, there’s all kinds in there,” Shigehiro said, not sounding particularly interested.

“I wonder what it’s called.”

Shigehiro shrugged and got off his beach chair. “You should ask Narumi. She knows that kind of thing.”

“But you were born here. You never learned the fish?”

“Not really. I was only here through high school, and besides, no one in the family was a fisherman.”

“Mom says you went to college in Tokyo and became an elite businessman.”

Shigehiro laughed. “She’s just pulling your leg,” he said. “No, your uncle was just a regular old employee. Now get changed and let’s go.”

“Right,” Kyohei said, picking up the plastic bag with his clothes and towel in it. When he got back from the changing rooms, Shigehiro pulled out his cell phone, pressed a few buttons, and put it to his ear.

“It’s me. Yep, he’s all done. See you at the same place as before.”

He hung up and closed the beach umbrella. It and the chair were rentals. Only the cooler was theirs. Kyohei picked it up and started to walk. His uncle followed behind him, having a little difficulty because his cane kept sinking into the sand.

Today was the first day the police hadn’t come up to the inn, which meant it was finally Kyohei’s chance to get that ride to the beach he’d been promised. His uncle wasn’t much interested in swimming, so he’d sat on the beach watching their stuff and chatting with Kyohei whenever he took a break from the waves.

They got back to the road and waited in front of a small convenience store until Setsuko arrived in the white van with “Green Rock Inn” written across the side. Shigehiro got into the backseat, struggling a bit to lift himself up. Kyohei took the passenger seat, like he had on the way down.

“Well? You have fun?” his aunt Setsuko asked.

“Yeah. And now I won’t have to put up with any crap.”

“Oh? From who?”

“The kids at school. If you don’t go swimming over summer break, the ones that did won’t let you forget it. It’s so lame. I mean, I guess I could just lie, but it’s better if I actually go.”

“That’s why you wanted to go? Whatever happened to swimming for the sake of swimming?” his uncle asked.

“Oh, I wanted to go swimming, sure. But it’s also important where you go swimming. I mean, if you just go to the local pool, that doesn’t count.”

His uncle grunted at that, and his aunt laughed.

They passed by Hari Cove Harbor. The big DESMEC survey boat he had seen there this morning was still at the dock. When he turned to look back at the road ahead, he spotted someone walking by the side of the road.

“Hey, it’s the professor,” he said, and pointed out the window.

Yukawa was walking with a light-colored jacket slung over his shoulder, a briefcase in one hand.

“Oh, you’re right,” Setsuko said, slowing down as they got near. She opened her window. The physicist didn’t seem to even notice them. He was looking down at the road beneath his feet, a preoccupied frown on his face.

“Mr. Yukawa?” Setsuko called out.

He smiled and stopped, and Setsuko stopped the car next to him. “All finished with work?”

“For today,” Yukawa said, his eyes going to the passenger seat.

Kyohei took off his seatbelt and leaned over toward the window on the driver’s side. “I went down to the beach with my uncle today!”

“Ah, finally made it, did you? Good.”

“If you’re heading back to the inn, would you like a ride?” Setsuko asked. “We’re on our way back ourselves.”

“You don’t mind?”

“Not at all.”

Yukawa hesitated just a moment, then went around to the side of the van, opened up the sliding door, and got in the backseat next to Shigehiro, nodding in greeting as he sat down.

“Those guys from DESMEC give you more trouble today?” Kyohei asked, twisting around to see him.

“Only the usual annoyances. That organization is too complicated for its own good. Too many captains and no one’s holding the steering wheel.”

“That doesn’t sound good with a big boat like that,” Kyohei said, his eyes going a little wider.

“It’s a metaphor,” Yukawa explained. “I mean that there’re so many people giving directions no one knows which way to turn. Not to change subject, but does this van belong to the inn? I saw the lettering on the side.”

“Yeah,” Shigehiro said. “We used to use it to pick up guests at the station, but they rarely ask these days. So we mostly just use it when I need a ride someplace.”

“You don’t drive?”

“Well, used to, but not anymore, not with this leg. Too hard to step on the brake.”

“Right, of course,” Yukawa said, looking around the inside of the van. “I was just wondering if the police gave you any trouble about the van.”

“Why would they?”

“Well, it’s just that I heard from the DESMEC folks that the police were asking everyone about cars parked in the area on the night Mr. Tsukahara went missing. They were checking vehicle owners, and even searching inside cars. It was quite the ordeal.”

“Oh, that,” Shigehiro said. “Yeah, the other night when those fellows from forensics came up to the inn, I’m pretty sure they checked the car then. Not sure what they were looking for, though.”

“Probably anything that could be a source of carbon monoxide,” Yukawa replied. “When those detectives from the prefectural police came to the inn the other day, asking after my alibi, I asked one of them whether they had found the source, and he became noticeably flustered. I’m guessing they found something that indicated Mr. Tsukahara died of carbon monoxide poisoning. But they didn’t know where, or how, thus the car-searching business.”

“What’s carbon monoxide?” Kyohei asked. “Is that like carbon dioxide?”

Yukawa looked a little surprised at the question, but then he nodded and glanced toward Shigehiro. “Actually, your uncle might be able to give you a better explanation of that than I can.” He looked toward Shigehiro. “Narumi tells me you used to work at Arima Engines?”

Shigehiro chuckled. “A long time ago, yes.” He looked at Kyohei. “Well, what do you know about carbon dioxide?”

“I know it’s causing global warming, right?”

“That’s right. It’s the gas generated when something burns. But when something burns badly, it produces a different kind of gas—that’s carbon monoxide.”

“And you die if you breathe it in?”

“If you breathe enough of it, sure.”

“That’s pretty scary. But what’s that got to do with cars?”

“Well,” Shigehiro said, wetting his lips before continuing. “Cars have tailpipes for exhaust, right? There’s carbon monoxide in the exhaust from cars.”

“Really?” Kyohei looked at Yukawa.

“Couldn’t have said it better myself,” Yukawa said, nodding to Shigehiro.

The old man chuckled and shook his head. “I haven’t forgotten everything—not yet, at least.”

“However, I might’ve added one thing,” Yukawa said, looking back toward Kyohei. “That is, I think there was another reason, besides the exhaust, that the police were interested in cars.”

“What’s that?”

“Well, like your uncle said, carbon monoxide is generated when something burns badly. What’s meant by ‘badly’ here is something burning without sufficient oxygen. You’ve heard about not using gas heaters in a room for a long time without opening the doors every once in a while? Well, picture burning something like charcoal in an even smaller space, like the inside of the car. That would generate a lot of carbon monoxide. I think the police suspect that that’s how Mr. Tsukahara was poisoned.”

Kyohei nodded, but immediately another question popped into his head. “Wait, but if that’s how he died, how did he end up on the rocks?”

Yukawa’s eyes narrowed, but then he smiled and shrugged, giving Kyohei’s uncle a glance before saying, “That, unfortunately, I can’t explain.”

Shigehiro was silent, looking out the window. Kyohei looked over at him, but his uncle must’ve been grumpy about something, because he was frowning. He glanced over at his aunt and was surprised to see a deep frown crossing her face as well.