After a good half an hour the light finally picked out something of interest. Set into the wall twenty metres away was a door, identical to the door of the lab. For a second he wondered if he hadn’t gone round in a big loop and ended up where he had started, but a glance behind him confirmed that the tunnel was very straight, and besides, he hadn’t passed the opening to the room with the giant vats of toxic substances.

The sight of the door gave him a definite objective, and a renewed determination. He switched the light off, attached it to his belt, and with his head down he reached forwards, gripped the floor grille, and pulled.

• • •

The bridge was a welcome oasis of calm for Lucya after the mayhem of the engine room and the horrors of deck eight. Back among the ordered rows of consoles and control panels it was almost possible to imagine that things were normal.

Seconds after she arrived there was a cacophony of whirring, beeping, and clicking as the power came back on and the various computers and systems all came back to life.

“Power! Thank you, Tom. So, any sign of the landing party?” She directed the question at Chuck, who had been maintaining the looking in her absence.

“The raft is on its way back. I would estimate ten minutes.”

“But?” Lucya looked at him quizzically. Something in the way he spoke made her think that all was not right.

He opened his mouth to reply, but was cut off by Erica pushing her way in front of him.

“Lucya! You’re back!”

“Hey, sweetie, are you okay?” She bent down and picked the girl up, hugging her tight. She surprised herself with just how happy she was to see the child.

“Dave showed me the maps. I’ve learnt the names of five countries!”

“That’s amazing, well done! Perhaps you’ll be a navigator one day? Telling the captain where to take the ship?”

“Is that what you do?”

“Yes,” Lucya said, smiling. “The captain does everything I tell him.” She caught Dave’s eye and gave him a wink. “Do you mind staying with Dave and Chuck a bit longer? I have to go and meet Jake. He’s bringing us something very important.”

“Will it make Daddy better?”

Lucya felt a pang of guilt, but she knew this wasn’t the right time to explain. “I don’t know about that,” she said softly. She told herself it wasn’t a lie, not really. She wasn’t getting the girl’s hopes up.

Erica looked into her eyes. “Is my daddy dead?” she asked simply.

Lucya was shocked. She hadn’t anticipated the question at all. Suddenly she felt all eyes were on her, not just Erica’s, but Dave’s and Chuck’s too. The atmosphere had changed in a second; only Erica seemed to be breathing.

“Yes,” Lucya whispered finally, her voice hoarse. The girl in her arms became a blur as her eyes ran with tears. “Yes, I’m so sorry, my love.”

“Don’t cry, Lucya.” Erica hugged her tightly. “Daddy wouldn’t want us to be sad. When Mummy died, he said she’d gone to heaven to watch over us, and that she’d be sad if we were sad all the time. Now Daddy’s in heaven with Mummy, isn’t he?”

Lucya sobbed and trembled uncontrollably, unable to speak. She didn’t believe in God or heaven, and events following the asteroid hadn’t done anything to change that. At the same time, she knew that this was a harmless lie, one that Erica could hang on to and draw strength from. “Yes,” she managed to croak. “I’m sure they’re in heaven together, looking down on you.”

Erica didn’t speak. Lucya could feel the girl’s tears run down her face and fall onto her own neck. The two of them stayed like that, bound together for a long time as each of them tried to come to terms with the truth.

It was Erica who pulled herself together first. Sniffing, she extracted herself from Lucya’s embrace, and with her tiny hand she dried first her own tears, then those of Lucya.

“Will you look after me now, Lucya? You and Jake?”

“Of course we will, my darling, of course!”

• • •

Opening the door, Jake realised, wasn’t going to be easy. Propping himself up on one hand, the handle was still out of reach.

He considered the problem. If he could get his shoulders higher, then his hand would reach further. He rolled himself over onto his back, then pushed himself into a sitting position. By continuing to push his hands against the floor he was able to raise his bottom a few centimetres from the ground and shuffle backwards. After a lot of shuffling, he was sitting with his back to the door. Reaching a hand over his head, the handle was almost within reach. The tips of his fingers brushed against it, although through the thick rubber that covered him, he couldn’t feel it.

Shaking his head to try and restore some clarity, he turned his attention to the objects he had with him. There was the torch of course, but it quickly became obvious that was not going to work. One try was enough to see that the rounded bulge of the lamp was incapable of getting any purchase against the handle; it just slipped right off.

His next idea was the sections of wetsuit sleeve that were pulled over his feet to offer additional protection from the ash. As he considered he wasn’t likely to make it outside, much less be walking anywhere, the sleeves were redundant. Leaning forwards he tried in vain to reach them, to pull them off. Jake kept himself reasonably fit; he was certainly no slouch. If he’d tried a day earlier, he would easily have been able to accomplish the manoeuvre. But with the bulk of the wetsuit around his body, and the paralysis in his legs spreading gradually towards his belly, he might as well have been reaching for the moon. His feet were even further out of range that the handle itself.

That left only one possibility: the gas mask. Vardy had suggested putting the masks back on when they had entered the hidden level, when it became clear what sort of work had been carried out down there. There was no specific threat, nothing they had seen suggested the air was anything but perfectly breathable. And yet, removing the mask felt like a giant step to Jake. Sending Ewan and the others on without him had been quite simple. Although doing so meant he would probably die in the tunnels, there was a disconnection between his action and the ultimate reaction. It was easy to be brave when the consequences were delayed. But removing the mask? That was an action that could directly and immediately lead to being poisoned, or gassed, or infected with a biological agent even more deadly than the virus that was already attacking his body. Removing the protection of the air filters could lead to a quicker death.

There was one other option, he told himself. He didn’t have to open the door. What was to be gained? It wasn’t as if he would find a miracle cure inside. And even if there were other survivors, what could they do for him? He risked infecting them if he went in.

“Hello?” he shouted as loud as he could. His voice was muffled by the mask, but the sound still carried well in the confines of the concrete tunnel. “Is there anyone there?” His lungs once again felt fit to burst. The damage caused by the gas and the effect of the virus had greatly reduced their capacity, and every word hurt as he shouted it. He hammered on the door with both fists. He banged his hands against the metal grate floor. The noise reverberated around him. Even when he stopped, it seemed to echo through his head. There was no answer. Nobody opened the door, and nobody came running to see who had entered their base. He was completely alone.

With nothing to lose, he made a snap decision. The mask was whipped off in one movement. Jake took a deep breath through his nose, opened his mouth, and let it out slowly. “In for a penny, in for a pound,” he said to himself quietly. The air was cool and had a strange smell to it, a metallic tang that stuck in the back of his throat. He took more breaths. He could feel his heart banging inside his chest, but the more he breathed, the calmer he became. If there was anything dangerous in the atmosphere, it wasn’t going to kill him immediately.