Jake brushed his hand gently over the panel. The rubber gloves made it hard to feel anything, but he was sure there were other switches or controls. There was no way of seeing exactly what they were because with a flicker, his torch finally gave out completely.

Sitting there in the dark, in pain, he rested his hand on the red handle. “In for a penny, in for a pound,” he repeated to himself, and pulled down the handle with a clunk.

• • •

“I think gas masks would be prudent at this stage, Janice,” Vardy said.

“Good plan.”

Both doctors picked up masks that had been brought to the makeshift lab by the submariners who had kitted it out while the landing party had been away.

They were in another store room down on deck one, near to Janice’s temporary morgue. Three tables borrowed from a restaurant had been assembled in a U shape. Vardy’s equipment from the Ambush occupied one table. On another was a rack of test tubes filled with blood. Each was neatly labelled with a name. Next to the tubes was a writing pad. Names corresponding to those on the tubes were listed on the topmost page, and alongside each were details including the age of the patient, how long they had been suffering or paralysed when the sample was taken, and where they were now.

On the third table was the Heimat Brinkdolph Gemini 5001 machine, and a plastic container filled with ash. It was this container that Vardy and Janice had turned their attention to.

With mask securely in place, Vardy cautiously opened it. He took a plastic beaker in one hand, turned to the tubes of blood, selected one, and poured a small sample into the bottom. Then with a plastic spoon he scooped up a tiny amount of ash and sprinkled it over the blood.

The reaction was almost instantaneous. The ash soaked up the blood and began to fizz and boil. Vardy and Janice both pulled away instinctively, but it lasted only a few seconds.

“Jesus! Have you ever seen anything like that?” Vardy said. He leaned over the beaker, staring inside.

“Never. What even happened? I mean, there was no visible gas given off. Where did the blood go? It seemed to boil, but there was no visible gas?”

Vardy picked up the beaker and swilled it around. The blood had indeed disappeared, leaving just the spoonful of ash which looked as dry as before.

He took another beaker, placed it on a digital scale, then put in some more ash.

“Four point three grams,” he said. “Stand back.” He poured a few drops of blood onto the ash, and they both watched as the exact same reaction took place. When he was sure it was over, he re-read the scale.

“Six point two grams. So the blood’s still there, but it’s changed form.”

“Russell, I’m sure this is fascinating, and another time it would be worthy of study, but we need to get this antiviral underway.”

“Of course, of course. But this is an important step. Now we know that we’re going to have to use a microscopic amount of ash to mutate the vaccine, otherwise we could end up turning the vaccine to ash.”

Janice nodded. “How microscopic does the amount have to be?”

“That’s what we need to figure out.”

They spent most of the next half an hour performing tests with the ash, combining it with blood, water, alcohol, and most other liquids they could get their hands on. The reaction was largely the same in every case, with the ash turning the liquid into more ash. But they did find a limit.

“So we’re agreed,” Vardy said finally. “Anything less than a tenth of a gram of ash dissolved in anything more than ten millilitres of liquid appears to be stable.”

“Uh huh. How much vaccine do you have?”

“There are three kits. Each one contains ten mills of flu vaccine. The 5001 machine can make more, but it will take too long. Do you want to prep the vaccine or the ash?”

“I’ll take the ash,” Janice said.

“Here, it goes in this.” Vardy handed her what looked like a tiny jam jar with a plastic lid. She placed it on the scale and set the readout to zero. Then, using the tip of a plastic spatula, she very carefully dropped just a few grains of the ash into it. The readout on the scale counted upwards, then back down, settling on a figure of 0.09 grams. She retrieved the jar and affixed the lid. Letting out the breath she had been holding, she handed the beaker to Vardy. “Over to you,” she said, relieved.

Vardy placed Janice’s jar in a small tray that protruded from the body of the Gemini 5001 and pressed a button. An electric motor whirred, and with a click the tray slid inside the machine.

“Just like loading a CD,” Janice observed.

Vardy took a second tiny jar and placed it on the scale. On the table with the test tubes was a bright orange box that looked like a tiny briefcase. He undid two plastic catches and lifted the lid. Inside were a dozen glass vials of different sizes, each labelled with the name of the vaccine it contained, and a date after which is should no longer be used. He selected the influenza vaccine. Taking a hypodermic needle and syringe, he pierced the seal on the vial and drew out the entire contents. The clear liquid was then injected into the small glass jar. With the lid securely in place, he put the jar into a second tray that sat waiting on the front of the blue machine, and pressed the button. With another whir and a click, the jar was pulled inside.

“What happens now?” Janice asked.

“Now? We wait. The machine will work its magic. It will constantly analyse the vaccine, and once it detects any kind of mutation, it will sound an alarm. We’ll need to manually verify with the microscope of course.”

“How long?”

“Hard to say. Could happen quickly, could take a few hours.”

“And if it works? How are we going to treat three thousand people when there are only two more vaccine kits?”

“The machine can make more. It functions as a miniature bioreactor. If this antiviral works, we hold some back and put it back into the machine along with a base liquid. It can’t create huge volumes. I won’t lie to you, it’s unlikely we can make enough to treat everyone in time, but I’m not going to worry about that until we know if this even works.”

• • •

For a few seconds it seemed as though nothing was going to happen. Then the rumbling started. A low, repetitive sound. Jake thought it sounded like a pump. Whatever it was, it was just the precursor to a much louder noise, a noise he knew very well: the noise of a huge diesel engine coming to life. The tiny red light had turned green, but it was still the only illumination in the room for another two and a half minutes. Precisely one hundred and fifty seconds after he pulled the handle came the unmistakable sound of a generator spinning up and then, quite suddenly, Jake was blinded by what seemed like a thousand floodlights all coming on at once. His arms flew up to cover his eyes, protecting them from the dazzling, brilliant light.

The noise around him abated slightly, as the diesel motor warmed up and settled down, and the initial load of so many lights coming on at once had been met. At the same time Jake’s eyes had begun to adjust, and through slotted fingers he could observe his surroundings properly for the first time.

The room he was in was huge. He’d only seen the hall containing the biohazard tanks with the aid of torchlight, but he had the impression this room was easily as big. He estimated that it must be at least half the size of level three, meaning that combined with the labs and the toxic store, level four was considerably larger than the others.

The panel with the lever that had started the generator stretched away for some distance. It was covered in meters and readouts, which as far as he could tell were all to do with the state of the electrical systems in the facility.

Much of the rest of the space was filled with giant tanks. Although they looked a lot like the toxic tanks they had seen before, these were clearly marked as being filled with diesel, no doubt for powering the generator, which from the sound of it was located somewhere further back, out of sight.