“Go!” Jake urged him.

“We’re coming back for you, Jake. Okay? We’re coming back!”

Vardy and Ewan had already started walking back up the dark tunnel, the sound of their footsteps disappearing into the distance. With one last look back at Jake, Ewan turned and followed them. Jake flicked off his torch, conserving the remaining battery, and stood alone in the darkness for a full minute before his legs gave way beneath him and he crashed to the ground.

• • •

“There, that all seems to be in order. All we need now is for your lot to flick a switch and power us up.” Tom Sanderson stood back, one hand on his hips, the other wiping a little sweat from his brow.

“We have a few checks to run on our side first,” Gunson said, “but we should have power restored within thirty minutes.” He held out a hand, and there was an awkward moment before Tom realised it was for him to shake. “Mr Sanderson, it’s been a pleasure working with you. If ever you would like a tour of our submarine…”

“All that new-fangled atomic power goes over my head, Mr Gunson. But perhaps I will take you up on your offer sometime.”

Lucya looked on, wondering if any of them would live long enough for that visit to happen. The immediate crisis had been averted, but it was going to take more than a retired engineer to save them from the virus working its way through the ship. “Thank you, Tom, for your help,” she said. “Now if you would be so kind as to give me your cabin number, I’m putting you on the list of essential personnel.”

Tom drew a sharp breath and gave her a look which suggested he had no intention of working on the ship in the future, but her expression made it clear that he really had no choice in the matter.

“I’m in 907, but I’m retired, I’ll remind you!”

“Nobody is retired in this community, Tom. Mr Gunson, thank you for your help. I have to get back to the bridge. The landing party may be back already, so the sooner we can have the power on the better.”

Gunson nodded at her, and she left the two men in the engine room to finish their discussion.

Lucya didn’t return directly to the bridge; she wanted to find out how Martin was doing. Even before she reached deck eight she knew things were bad. From two decks below she could hear the moaning and howling, the sounds of sick people in great pain. Some were shouting, demanding help, or calling out the names of their loved ones. Some were simply wailing and crying. She could see through open cabin doors that those were the families, the people who weren’t yet sick but who were forced to watch the people they loved suffer, all the time knowing they would probably be next.

People she didn’t recognise were charging about, flitting from cabin to cabin dispensing wet towels and kind words. She assumed these must be the new recruits, the nurses called up to help. They looked exhausted, but they worked without complaint.

Janice was in cabin 845. She was pulling a sheet up over a lifeless body, whose face was obscured from view. For a moment, Lucya’s heart leaped into her mouth.

“Martin?” She whispered the name, and felt the colour drain from her cheeks. Janice looked up at her and shook her head.

“No, not Martin. I don’t know his name. The poor soul was in a cabin alone.”

Lucya let out a sigh of relief, then felt immediately guilty. This man’s death was as much of a tragedy as Martin’s would have been, but she didn’t know him, so it was impossible for her to feel the loss the same way.

“If there’s time, I will take him down and do an autopsy. As far as we know, Kiera and Barry were the first cases after Scott. He died quickly because of his pre-existing condition. Kiera is in a very bad way, but she is hanging on. If this man was infected after her, I’d like to know why he died first.”

“His age? He was weaker, perhaps?”

“That is the most likely, yes. Or it could be that he was infected earlier. As he was alone, nobody reported his condition to the medical staff. The nurses only found him because they were looking for empty cabins into which to put the sick coming up from other decks.”

“And Martin?”

“He’ll be okay. He’s not conscious, but his vital signs are all good. We’ll know more when he wakes up. Do you want to see him?”

Lucya considered the question. “No, I don’t think so. I should get back to the bridge. I wanted to know that he was okay, that’s the main thing.”

A sound from behind her made her turn around. A child, maybe ten years old, stood crying in the doorway.

“Hello, my love,” Janice said, crouching down to his height. “What’s your name then?”

“Robert,” the boy whimpered. He sounded American.

“And what’s the matter, Robert, my darling? Why are you upset?”

“My mom and dad are sick and nobody has come to help them.”

“Okay, honey, can you show me where they are?” The boy nodded, and took the hand she offered. “I’m sorry, I have to go,” Janice said to Lucya.

“Of course. I’ll be on the bridge. If there’s anything we can do, anything you need…”

“Sure thing, thanks, Lucya.”

• • •

Despite the lack of light, Jake was surprised to find he could make good progress through the deep passageway of level four, even without the use of his legs. The grate on the floor, which he realised with some alarm was designed to allow spillages of who-knew-what to be washed away into the channel beneath, was the perfect surface to drag himself along. He reached out his arms, locked his fingers into the holes, and pulled himself forwards. It was slow going, dirty, uncomfortable, and physically exhausting, but he felt that at least he was doing something.

He had considered the fact that by not staying put, he was making himself more difficult to find. But then, he reasoned, there was little chance that the others would ever come back for him, not really. They all knew that Vardy’s idea for a cure was a long shot. Such things normally required years of development, not hours. Even if by some miracle they did make it work, they would have to treat the others who were infected before him. The machine didn’t look like it was capable of producing industrial quantities of anything. By the time they got back to him, he’d be long since dead. He had known all of this when he sent them on their way. He knew he was probably signing his own death sentence.

And so, in an effort to keep his mind from dwelling on his likely demise, to stop himself from thinking about Lucya, he had decided to explore the rest of level four while he still had some mobility. One question continued to burn in his mind. Where had all the people from the base gone? Six thousand, McNair had said. Six thousand people had worked on the base. They had had hours of warning before the asteroid hit, ample time to get as many people as humanly possible into the relative safety of the underground levels. And yet they hadn’t seen evidence of a single soul having been inside. The place was tidy, clean. Level three had looked virtually unused. Although they hadn’t explored levels one and two, they had passed through on their way down the stairs. The lack of light and any sound on those levels, plus the fact that nobody had come running to see what the noise was when they had blown the lift floor, suggested they were just as empty, as did the pressurised halon they had discovered.

That left the hidden level four, a place so different to the others above that it was possible to imagine there were people hiding out down here, as far away from the surface as they could get. Spurred on by this thought, the idea that maybe, just maybe, he might find more survivors in this secret sub-basement, he continued to pull himself through the tunnel.

Every now and then his gloved fingers would touch the concrete of the wall and he would correct his course. He used the torch every fifteen metres or so, to check on his progress, and to try and see where the tunnel led. The battery was draining; the beam was no longer able to cut deep into the darkness. His eyes had fully adjusted though, so the feeble illumination it was still able to offer was enough to keep him on track.