Devil's Gate

46

USS Truxton, July 1

PAUL TROUT SAT with a sonar operator in the air-conditioned comfort of a darkened control room on the USS Truxton. The space around them was given over to flat-screen monitors and computer controls. Part of it resembled a mixing studio, which was appropriate as the recorded sounds were sliced and diced and spliced back together in segments.

Part of the problem in getting any coherent information out of the signal was the nature of the Matador’s sonar system. It was twenty years old and had been designed to map the seafloor in broad swaths for various survey teams. In its active mode, a sound wave would be sent from a bell on the bottom of the Matador and bounced off the floor and collected by the system’s hydrophones. In passive mode, it simply listened and picked up ambient noises.

Another limitation was that each hydrophone pointed downward, covering a thin but widening swath as it penetrated into the depths, like a cone of light beneath a streetlamp. The problem was, like the metaphorical streetlamp on an incredibly dark night, nothing outside the cone was visible.

One of the Truxton’s anti-submarine warfare operators, Petty Officer Collier, was with them. A wiry young man with a calm demeanor, Collier had been slicing and dicing the tapes with them for hours. While Paul found it tedious, the petty officer seemed to latch onto even the smallest thing and get enthusiastic about starting the process over.

“Okay, here we go,” he said for the fiftieth time.

Paul put a hand to the soft-padded headset and pressed it into his ears. He saw Gamay click a pen into writing mode and tilt her head in anticipation. The young petty officer pressed “Play,” and Paul heard the familiar sounds of the tape beginning for the umpteenth time. Each time there had been a slight difference as the ensign and his computers filtered out background noise or other sounds. This time, he’d added something.

“To better orient you with what you’re actually hearing,” Petty Officer Collier said, “we’ve synced up your voice records from communications with the surface with the tape.” This time, as the playback ticked over, Paul heard his own voice — it was he and Gamay, bantering with the Matador on the surface and then with each other.

It was all so surreal. It was him, he knew it was him, but he couldn’t recall saying any of the things he was hearing. Couldn’t recall what he was doing while the words were being spoken.

Gamay looked over at him. “Anything?” “You mean memory-wise?”

She nodded.

“No.”

She looked back at her notes, and the tape continued. Finally, it reached the point of the initial attack.

Paul pressed the headphones against his ears once again but kept his eyes on Gamay. Each time it reached this point she got agitated. And this run-through was no different. She’d already begun tapping her pen nervously.

“I’m taking her deeper into the ship,” he heard Gamay say on the tape in reference to Rapunzel.

A slight change in the background noise was detected, marked by a spike in certain frequencies on the computer screen.

Several seconds later the Matador’s controller spoke.

“Paul, we’re picking up a sonar contact.” “What kind?”

“Unknown. West of you and very faint. But moving fast.” Paul listened to the sound. It was more discernible this time, as if it had been enhanced.

He heard his own voice ask if the sound was mechanical or natural, and then, as the signal grew louder, the controller’s voice changed in pitch as well, suddenly gaining half an octave.

“Mechanical or natural?”

“Unknown… It’s small…” “It’s a torpedo. Two of them, heading your way.” “Stop the tape,” Paul said. “Play back the last twenty seconds.” “I don’t think we need to, Paul,” Gamay said. “It’s useless.” “No,” Paul said. “I heard something. Something I didn’t hear last time. Play it back.” Gamay turned from him, looking frustrated and pensive. Her fingernails were chewed down to nothing, and she kept looking around, focusing on the door and the clock like a kid in the last class on the last day of school.

Paul guessed that listening to the tape over and over again was forcing her to relive the incident and he understood how it might be affecting her, but despite his repeated suggestions she would not leave him to do it alone.

The tape played again, and Paul listened closely.

As it finished, he asked for one more listen.

He saw Gamay gulp at an imaginary lump in her throat as the tape ran forward again.

“Paul, we’re picking up a sonar contact.” “What kind?”

“Unknown. West of you and very faint. But moving fast.” “Stop!” Paul said. “Right there.” Gamay took her headset off and put it down on the table. “I have to get some air,” she said.

Paul nodded and watched her leave the room. In a bizarre way his memory loss seemed to be helping them, as he had no emotional attachment to what had gone down. It was an investigation like all the others. A mystery he wanted to solve. But it dredged up no particular feelings for him.

“Can you isolate the vibration and remove the voice track?” Paul asked.

“Sure,” the petty officer said.

It took a minute, and then it was ready and playing again. There was something else blocking the sound. Paul looked at the computer screen. A frequency chart showed a bunch of low-level background noises and two major vibration sources. One was on a slightly lower band than the other.

“What’s this?” he asked, pointing to the spike on the chart.

“That’s the Grouper’s motor signature,” the ensign said.

“Can you pull it out?”

Collier nodded, and a few seconds later indicated that he was ready.

“Go,” Paul said.

This time, as the playback went through, Paul was sure of what he was hearing. He didn’t know what it meant, but it wasn’t his imagination.

He pointed to the other frequency spike. “Can you eliminate all other background noise and just play this? And can you enhance it?” “Mr. Trout,” the petty officer said, “the government makes sure we have the best equipment in the world. I can make it play the ‘Star-Spangled Banner,’ if you want.” Paul laughed. “Just make this sound wave louder,” he said, “and stretch it out a bit.” This time, as the playback came, it sounded a little like a moped speeding toward him on an empty city street. No other noise, no urgent shouts of inbound torpedoes, just a whiny vibration that grew slightly louder and then lowered its pitch, not once but twice. As if it had passed them and was turning away.

“Is that what I think it is?” Paul asked.

The petty officer played the tape one more time and nodded.

“Compression,” he said. “The initial sound is compressed to high frequency because the source is coming toward the Grouper, and on the last three seconds of tape the sound is stretched out to lower frequency because the source is moving away from the Grouper.” “Like a train whistle,” Paul said, “or a car passing you on the street. The vehicle is still making the same sound, but your perception is different. So it can’t be the torpedoes.” “Nope,” the petty officer said. “It’s definitely a vehicle. From the sound of it, I’d say it’s two vehicles.” Paul nodded; that’s what he was thinking. “But why didn’t we hear them before?” “All the distortion,” Collier said. “And the torpedoes. In fact, the signature is being picked up in almost the same frequency bands as the torpedoes.” “What does that mean?”

“To me, Mr. Trout, that means you were attacked by something small and fast. Submarines making high rpms with small propellers, much like a torpedo.” “Not one big submarine but two small ones,” Paul said. He wasn’t sure what that meant, but he guessed it would bring the mother ship theory back into play. At the very least, they were making progress.

Collier ran it one last time just to be sure. The sound was only audible for a couple of seconds in real time before the noise of the torpedoes drowned it out.

Collier took his headset off. “I’ll inform the captain. And we’ll do some more work on this.” “You want me to stick around?” Paul asked.

“I think you have some work of your own to do, Mr. Trout.” He nodded upward as if to suggest Paul go topside.

“Right,” Paul said. He put his headset down, got up, and made his way through the bulkhead door.

Two minutes later he stepped out onto the Truxton’s aft deck.

Sunshine, fresh air, and the sound of thumping helicopter blades greeted him. A stone gray SH-60B Seahawk was descending toward the helipad with a payload suspended beneath it.

He found Gamay watching it and moved up beside her.

“I think we’ve found something,” he shouted over the noise.

She didn’t respond except to acknowledge that he was there.

“I think we’ve isolated the acoustics of the sub that attacked us,” he explained. “It was actually two subs.” “Good,” she said, sounding anything but excited.

“I thought you’d be happy,” he said. “We don’t have to listen to the tape anymore. Why are you so upset?” She looked at him and then nodded toward the helicopter. “What’s that doing here?” Paul looked over. The payload beneath the helicopter was being lowered to the deck in a cradle. It was now close enough that Paul could make out what it was: a small submersible. Attached to the rear of the sub was a package of mechanical equipment and a human-shaped figure made of metal. Rapunzel.

“Dirk sent it over,” Paul said.

“You knew about this?”

“He told me this morning,” Paul said. “It’s only a contingency. Just in case we need it.” Gamay said nothing. She just shook her head angrily, glared at him for a second, and then pushed past him and went back inside the ship.