The two men lowered Lucya into the raft. Ewan saw the body just as he was putting her legs down. He jumped, and fell backwards over one of the inflatable chambers, landing on the rubber floor.

“Bloody hell! There’s a body in the raft!”

“Ah, yes. I found him in there. In fact,” Jake said, positioning Lucya in a way he thought would be most comfortable for her should she regain consciousness, “I don’t think this is the same raft we came over in. Did you bring a different one this time?”

“No, why?”

“The one we used before didn’t have these markings on it, did it?” He pointed to the rear inflatable chamber. Six strange symbols were inscribed upon it. Jake wasn’t accustomed to guessing, but had someone forced him to do so he would have said the symbols had been drawn on by hand using chalk.

“No, those weren’t there before. Maybe the dead guy with no head drew them on?” Ewan was trying not to look directly at the body.

“Doubt it,” Jake said simply. “By the look of him, I’d say he died before today. Janice can take a look at him when we get back, see what she makes of it all. Now there are two of them, she can look for commonalities. Okay, ready? Let’s get going.”

Ewan was only too happy to turn round and row. That way he wasn’t looking at the slowly decomposing human being wedged into the middle of the craft.

It was tough going, paddling across the loch. The wind wasn’t favourable; although it wasn’t directly against them, it was pushing them well off course. It was all Jake could do to keep them facing in the right direction, while Ewan propelled them ever forwards. It didn’t seem to make any difference how hard they paddled; the ship remained obstinately stuck out of reach.

Then it started to rain. Not drizzle, or spots of rain. This was a downpour. Torrential rain, drops the size of peas.

The canopy, which Jake had folded away before rowing back to the shore, was hastily erected by the two men. By the time they had covered the inflatable, several centimetres of water had already accumulated in the bottom.

“We have to bail it out!” Jake yelled, trying to remove the water with his cupped hands. “Lucya is going to freeze to death lying in this.”

“Jake, it’s no good. We’ll never get it out. We have to move her, come on.”

“Where?”

“Try and get her onto the middle seat.”

He nodded, and they pulled her up out of the water and into a sitting position on the inflatable sausage that served as a seat and as added buoyancy. It quickly became clear that their plan was not going to work, as she simply flopped and rolled around.

“We can’t both hold her up, we have to row!” Jake shouted. He could hardly even hear himself over the sound of the pounding rain on the canopy, and the howling wind outside.

“We can’t put her back in the water!” Ewan cried.

Both realised the solution at the same time.

“We can’t!” Ewan said. “It’s disgusting! How do we know she won’t catch something?”

“She’s already caught something, Ewan. We have to! It’s not for long. We have to get back to the ship!”

The submariner knew Jake was right. Screwing his face up, he helped Jake lower Lucya on top of the decapitated man. Her back was against his, stretched out in the middle of the raft.

“See? She’s out of the water now!” Jake screamed over the constant noise. “Now we row!”

“I don’t think we can! Not with the canopy up!”

“We can’t take it down; we’ll drown!”

Jake poked his head outside. The wind had blown them further away from the ship. They were drifting up the loch, towards who knew where? He ducked back under the shelter of the bright orange fabric and grabbed the end of the rope that circled the raft.

“What are you doing?” Ewan shouted. He watched as Jake tied the rope around his own waist.

“I’m going to swim for it!” Jake replied. “It’s the only way. Like you said, we can’t row.”

“You’ll never make it!”

“Yes I will. I feel fighting fit. And Lucya needs medical attention. What else can we do? Wait around and hope they send someone for us? How? There aren’t even any boats they can send!”

“Then I’m coming with you!”

Jake shrugged, then, quite without warning, he pulled open the canopy and dived straight out and into the freezing and churning waters of the Scottish loch.

Twenty-Seven

“I DON’T GET it. I just don’t get it,” Vardy said. He was pacing around the room, looking up at the ceiling. Chipped white paint pitted with spots of rust looked back at him. “How can the virus just die in the children’s blood?”

“We’re back to where we started. We have to find the common element, whatever is killing it,” Janice said. She rocked back on her chair, rubbing her eyes.

“But there’s no evidence of anything attacking it. It’s like it just…dies.”

“So what you’re saying,” Mandy said, “is that there’s not something extra in the children’s blood. There’s not some additional agent that’s killing the virus. Could it be the opposite?”

Vardy stopped pacing and stared at the nurse. “What do you mean? The opposite?”

“I mean if there’s not something extra in the children’s blood, something that isn’t in the adult blood, perhaps it’s the other way around. Maybe, and I have no idea if this is possible, I’m just an outsider looking in at your work, but maybe there’s something missing in the children’s blood?”

Vardy sighed. “I don’t see what difference that would make. Something is killing the virus when it enters infant blood. That something clearly isn’t present in adult blood.”

“No, I see what she means,” Janice said. She got to her feet and joined the other two, her eyes bright with excitement. “Mandy could be right. What if there is something in adult blood that the virus needs, to survive? If that something, whatever it is, is not available to the virus in the younger blood, it can’t survive. That would explain why we don’t see anything attacking it! Because nothing is attacking it. It’s dying through lack of…”

“Of what?” Vardy asked.

“That’s what we need to find out. We’ve only looked at infected blood samples. We haven’t seen what happens when we introduce the virus to clean, uninfected blood. We have to observe the very first stages of infection, to understand the difference with the infant blood.”

“Okay, say you’re right, and I’m not convinced, by the way. Tell me, where are we going to find clean blood on this ship? Almost everyone must have been exposed by now. Even the Ambush has been exposed. Even if we could find someone who hasn’t been exposed, who is going to draw their blood? If any of us try, we’ll be exposing them to the virus!”

“You mean you don’t have a transfusion program on your submarine? You don’t keep stocks of blood on board?”

Vardy remained silent for a second, then broke into a broad smile. “Okay, you got me. Missing the obvious again. How did you know? I thought that was classified.”

“I guess not. I remember reading something about a trial run. It was reported in a medical journal.”

It didn’t take long to get the banked blood delivered to the laboratory. A phone call to the bridge, who in turn called the Ambush, was enough to get a submariner over with a refrigerated pack within ten minutes. Vardy chuckled to himself when he saw the name of the donor.

“If this works,” he said, “Captain Coote can claim to have had a hand—or a hand’s-worth of blood—in beating this virus.”

Janice prepared a sterile Petri dish with a sample of Coote’s uninfected blood. Under the microscope, she injected a few drops of an adult’s infected sample, and watched what happened.

• • •

Swimming the loch, with the life raft in tow, was the greatest physical challenge Jake had ever undertaken. Even under favourable circumstances it would have been a monumental undertaking. Yet the circumstances were anything but favourable. The water itself was freezing cold, and seemed to be getting colder the further from land he swam. His wetsuit offered some protection, but the longer he spent in the loch, the deeper into his muscles the cold penetrated. He shivered almost uncontrollably as his body tried desperately to generate heat. All it achieved was the redirection of energy that he needed to power his arms and legs.