“Of course.” He turned to the nurse. “Thank you. We’ll take it from here.” A nod to Cummings, and the sailor took the chair in hand, wheeling it out through the exit and over the new temporary walkway. Jake and the others followed.

Jake had never thought of the bridge of the Spirit of Arcadia as being particularly plush. Indeed, its rows of dull consoles were a world away from the more opulent passenger areas of the ship. Compared to the Lance, though, the Arcadia was the height of luxury. The research ship’s bridge could best be described as functional. Everything that was required to navigate safely through the polar waters was present and correct. No more, and no less. If the Norwegian Polar Institute that operated her had spent money anywhere, it must have been in the labs, Jake thought. It certainly wasn’t on the bridge.

Daniel Barrett immediately took up the helm. The others looked expectantly at Jake. There was no captain’s chair to speak of, no pedestal where he could issue orders from on high. It was a simple room, with all the controls laid out along the front. He stood in the middle of the console, and gave the order. “Helm, take us out when ready. Due north, fifteen knots.”

“Aye, Captain.”

Jake looked at the man, opened his mouth to speak, but saw Daniel grinning and changed his mind.

Twenty-Seven

THE NOISE, WHEN it started, was so loud it made Lucya’s head spin. She was too close to the pipe’s entrance; she should have made better progress before they restarted the giant fans. The whirring sound reverberated around her, and for a short while she became completely disoriented in the blackness of the tunnel. A thought flashed through her mind: this was what being buried alive must feel like. Except it wouldn’t have felt like that, because an instant later a jet of cold air hit her like a tornado, rolling over her body, under her legs, wrapping itself around her, clutching her tight. Before she could stop herself, Lucya gave a shriek. She shaped her mouth shut and swallowed the rest of the sound that had tried to escape. She hoped beyond hope that her involuntary gasp would be lost in the swirling air.

The fan regulated itself to a steady speed, and the air flow settled accordingly. Even the noise level dropped off, just a touch.

Lucya realised she had her eyes closed tight. She opened them again, but it made no difference. No light ventured into the tube.

With her hands outstretched in front of her, she placed her palms flat against the curved interior and pulled herself forwards. At the same time, she bent her legs as far as the confined space would allow, and pushed with the toes of her rubber gym shoes. They gave good grip against the slippery surface, but the limited amount of room meant she could move no more than a couple of inches at a time. While she wriggled along on her belly, painfully slowly, her mind recalled the technical drawings. Not To Scale, they had said. Martin had estimated the distance nonetheless. It was at least a hundred metres, and a section of that was ‘uphill’, as the pipeline went up a deck. At her current pace, she realised with horror, she had no chance of even reaching the conference room before the deadline, let alone giving the virus time to work.

• • •

“How do we know the mystery submarine won’t torpedo us?” Daniel asked. “What if they think we’re the Ambush and try and take us out? Or worse, what if the Ambush thinks we’re the unfriendly sub, and they sink us?”

“I’ve been on board the Ambush. I’ve seen their sonar at work. They’ll see us, certainly, and they’ll know we’re the Lance. They knew the Lance was the Lance even before we knew about the Lance…if that makes sense?” Jake scratched his head.

“Yeah, I think so.”

“I would imagine the other submarine is similarly equipped.”

“So that begs the question” — Daniel wasn’t done yet — “how come they can’t spot each other? The Ambush is a damn sight bigger than this boat.”

It was Bodil who answered. “Modern nuclear submarines are virtually undetectable. They use a range of stealth technologies. Anechoic tiles covering the hull, highly advanced propeller designs that don’t boil the water around them and therefore don’t make noises, even the shape of the hull itself is designed to reduce its radar and sonar signature. If a submarine doesn’t want to be found, it won’t be found.”

“So how are we going to find them?” Daniel looked confused.

“We have an advantage. We can use active sonar.”

“Wait, they must have sonar too, right? If their military sonar can’t find a whacking great big submerged vessel…”

Bodil smiled. She was in her element, talking about her specialist subject to someone interested in listening. Indeed, all four sailors and Jake were watching her intently, hanging on her every word. “There are two kinds of sonar: active and passive. Active sonar works like radar, but uses sound waves instead of radio waves.”

“Like a dolphin?” one of the men asked.

“Yes, exactly. We send out a noise, and when it bounces off something, we hear the echo. Using the time it takes for the echo to come back, we can work out the distance to the object—”

“And by sending out a lot of noise, you can basically map the size of the object.” The sailor looked pleased with himself. The Lance hit a wave, and bounced and juddered, wiping the smile from his face.

“Right. Now I’m no expert on military systems, but I know the active sonar on this boat can pick up objects as small as a single fish. Now, you see perhaps the problem the submarines have?”

Daniel offered up an explanation. “If they use active sonar, the other submarine will detect the sounds they’re sending out. They’ll give away their position.”

“Precisely. So while they are hiding out, they must rely on passive sonar. They can only listen for noises already out there.”

“Like the sound of our propeller.”

“That’s one source, yes. The Spirit of Arcadia will also be making a lot of noise.”

“Really?” Jake looked around. “But she’s not moving. Her main engines aren’t even running, only the electric generator.”

“That generator will cause vibrations. Even the people moving around on the ship will cause vibrations. The passive sonar will pick up all of this noise. Both submarines will know exactly where she, and we, are located.”

“Well I guess that means they’re not planning on sinking her. They could already have done so,” Daniel said, the relief evident in his voice. “So the two submarines are both hiding out, each one waiting for the other to make a noise and give away its position?”

“Most likely.”

“We don’t know that for sure, though,” Jake added. “The unfriendly sub could have gone, left the area. Unlikely, but possible.”

They sailed on for a while, the drone of the powerful diesel engine below and the occasional wave breaking over the bow the only sounds. Each of them was lost in their thoughts.

Sailing on the smaller ship, Jake was reminded of the boat trips his father had taken him on as a child. He’d never really wanted to go, but he hated to see the disappointment on the old man’s face, so when his mother had insisted, he had always obliged. They’d hitch rides on friends’ fishing boats, or hire or borrow sailing boats for a weekend. It didn’t matter to his dad as long as they were out on the water. It was as if his father thought that if Jake was exposed to the sea for long enough, he would develop a love of the ocean as deep as his own. It never happened, but Jake did develop a habit of going along with his father’s wishes, putting up less and less resistance as time went by, ultimately leading him to take a job as an engineer on a small cruise liner. By then it was too late; his career path was set, and although he escaped the engine room and got into the ranks of the bridge officers, he had never escaped the sea.