“So you didn’t lose anyone?”

“I would not say that. You will have time to grieve, Mandy, you will have time to come to terms with this. Perhaps it is for the best that this will happen gradually. Right now, the people on this ship need us to be strong.”

“You’re right, I’m sorry for being such a soppy wuss. Listen, I have to grab some painkillers and dressings and go and help that girl’s mother. We start leaving them in their own cabins now, right?”

Grau looked around at the packed suite of rooms. “Yes, we have no choice. We also have very few painkillers left. We must cut the dose in half.”

“Half a dose won’t have much effect, you know that.”

“Yes, I do, but what can we do? Give half a dose to many, or a full dose to just a few?”

Mandy nodded. She understood only too well. As she set off in search of the medication, the phone in the suite rang. Grau picked it up.

“Hello, medical, Doctor Lister speaking…Hello, Janice, how are you getting on?”

As he listened, his expression of sadness turned to one of shock. “Are you sure?…How sure?…I see. I will inform the captain immediately.”

He replaced the receiver, all colour drained from his face.

• • •

It was obvious to Lucya that something was very wrong when she opened the door to the bridge. Grau had told her not to let anyone in or out, but as it was he himself who had knocked, had insisted on coming in, she had obliged.

The doctor was wearing gloves and a face mask. He waited until the door was closed behind him before removing the protection from his face.

“How is the girl?” he asked.

“She’s fine. She’s over there with Dave, keeping lookout. We’re entering the Irish Sea. It’s really quite beautiful, even with the ash.”

“Where is Jake? I need to talk to him urgently.”

“He’s on the Ambush. He went to check out this other raft and talk to Coote.”

“He is where?” Grau’s face turned red, his eyes bulged, disbelieving. “Did you not understand what I said about not letting anyone in or out of here? How could he be so stupid? Oh my, he has no idea what he has done!”

“Doctor Lister, calm down. He went before you called. Nobody else has been or gone since then. To be honest it’s getting awkward. I could use a natural break. Are you sure we can’t use the toilets just outside?”

“No! This bridge is under quarantine!” Grau sat down on a tall chair at the map table. “I am sorry, Lucya, this is not your fault. But Jake has put the lives of all those aboard the submarine in grave danger.”

“You mean the illness? But Jake’s fine, he’s not unwell. If anyone is in danger, surely it’s you? You’ve been treating them. You’ve been touching them.” Lucya pulled away from him slightly at the thought that he might be a carrier of the mystery disease.

“It has nothing to do with touching, Lucya. That is precisely the problem. Our pathologist has been studying how this disease spreads. She is certain, almost certain,” he corrected himself, “that the disease is caused by an airborne virus.”

Instinctively Lucya’s hand covered her mouth and she stepped away from the doctor, her eyes wide. Grau shook his head slowly.

“Sorry, but it is already too late. The girl must be infected. Jake too. And now he is aboard the submarine, spreading the virus further. We could have tried to contain it on this ship, although I think our efforts are in vain. There has already been too much free movement between decks; we have little chance of restricting it to a single level. The Ambush, though, that was safe. They could have survived without us.”

“You think we’re all going to die, is that what you’re saying, Grau?”

“I would never be so dramatic as to suggest such a thing. But I must concede that our chances are not good. We are not equipped to deal with a deadly virus, much less an unknown deadly virus. Our procedures as a cruise ship are clear. In cases like this, we quarantine affected decks and await outside medical assistance. Alas, we have no luxury of help coming from the outside.”

“Grau, there has to be something we can do? We can’t just give up hope, not after all we’ve already been through!”

“We can make people comfortable. We can continue to try combinations of antibiotics. Even if we found a cocktail of drugs that was effective, we do not have enough medication to treat everyone on board, and we have no means of fabricating more. And if this is a virus rather than a bacterial infection, then antibiotics will do no good anyway.” He fell silent; Erica was headed his way.

“Hi, Doctor Lister, how’s Daddy? Have you come to fetch me so I can see him?”

Lucya closed her eyes, wishing she was somewhere else. They couldn’t put off telling the girl her father was dead forever, but now wasn’t the time.

“Erica, how are you feeling? Do you have any pain anywhere? Have you fallen over?” Grau looked at her, a curious expression on his face.

She returned his regard, her head tilted slightly to one side. “I feel fine, it’s Daddy who’s ill, not me! When are we going to see him?”

“Your daddy is sleeping, we’d best not disturb him now. He wanted me to make sure you are alright, he thinks you might have caught his illness. Would you let me examine you, to give you a quick check-up?”

“Why does daddy think I’m not well? That’s silly!”

“Yes, it probably is. But he is very worried about you. If he worries, it will be more difficult for him to get better. So can I examine you for him?”

Lucya pulled Grau to one side and whispered urgently in his ear. “What are you doing? You can’t lie to her about her dad! What’s she going to think when she finds out?”

“Look at her, Lucya. Look!” Grau hadn’t taken his eyes off Erica. “She looks perfectly healthy. Scott was the second patient to go down with this. Kiera and Barry caught it from him. The girl should be very sick by now, but she is not. If she has some kind of immunity, we have to find out!”

Lucya turned to look at the child, who did indeed appear to be in perfect health. She made a snap decision. “Erica, darling, it’s okay, Doctor Lister is very kind, and it won’t take long to give you a check-up. Is that okay?”

“Will you come with me, Lucya?”

“Yes, of course I will.”

“Mmm, if that’s what Daddy wants, I s’pose it’s alright.”

• • •

Jake returned to the bridge to find it almost deserted. Only Dave and Chuck were around, the former manning the radar, the trainee on the helm.

“Where did Lucya go?” he asked, looking around.

“Off with Grau and the girl,” Dave said. “He’s not best pleased with you. From the little I heard, this virus is airborne. You’re probably carrying it, and you probably carried it right onto the sub. Now he thinks the girl might be the key to a miracle cure, so they’ve taken her to his cabin to check her over and take some blood. He wants you down there the instant you get back.”

Jake looked out of the window. They were somewhere between Northern Ireland and Scotland, ashen land clearly visible on both sides.

“How long before we reach Faslane?” he asked.

Dave checked the screen in front of him. “Another hour and we’ll be entering the Firth of Clyde. From there, a good twelve hours I’d say. We should hit Gare Loch by oh-six hundred hours, maybe oh-seven. With Ambush out of the water we’re running slower than we could.”

“Chuck, are you okay on the helm for now?”

“Yes, sir. The ship is sailing herself. This close to land we have full radar navigation. I’m hands-off, mostly keeping watch.”

“Okay, in that case I suppose I have no excuses. Time to face the music. Call if you need me.”

• • •

“You’re being a very brave girl, Erica. Doctor Lister is almost done. He just needs to give you a tiny little pinprick, it won’t hurt a bit, I promise.”

“I hate needles!”

“Doctor Lister has special magic needles that don’t hurt, it will be fine, trust me.”