“Simple,” said Lockhart, pointing to the blackboard. “We make our way to hall number 44 here, which is where I suspect the gas is held. It may be at this stage that we’ll have to engage the enemy, but I’m hoping that the bluff will hold. We’ll then park the truck as close to the chemical store as possible, and deal with the gas.”

“But how?” Maclaren asked.

“I’ll tell you that in a moment,” said Lockhart.

“There seems so much that can go wrong,” said Catchpole. “We could be stopped at any moment. Someone could smell a rat….”

“I know, I know,” said Lockhart. “But if you’ve got a better idea, then let’s hear it. Remember, simple plans have less to go wrong with them. Don’t forget, Mittelbau is a vast place—they have such comings and goings every day. We’ll be just another set of faces, just another unit of bored men looking forward to a Sunday afternoon off. And because it’s the weekend, those on duty will probably be feeling a little more slack.”

“It sounds mad!” said Prain.

“Perhaps,” said Lockhart, “but it would be a greater madness not to try. Just imagine the whole of London choking to death on an invisible cloud of gas. It would be the worst terror on earth, destruction and murder on a scale never seen before. We can’t just sit by and let it happen. Many of you have families in London—are you willing just to let them die? And where will they hit next? Manchester? Liverpool? The whole British population could be eradicated. Just think of it for a minute.”

The men did so, most of them with their arms folded, looking at the floor or out of the window. Each thought of his family back home, trying to imagine a terror that was almost inconceivable. They pictured their mothers, their girlfriends, their fathers—all choking to death. They saw heaps of bodies lying in the streets, a vision so grim, so evil, that a collective shudder went around the room.

“And where do we go if we get away?” Prain asked.

Lockhart had thought about that, but had put it low down on his list of priorities. In his heart, he knew that the chance of any of them getting out alive was appallingly slim.

“I have a contact who has a safe house in Nordhausen,” said Lockhart. “We will make our way there afterwards.”

“Who’s your contact?”

“I cannot tell you,” said Lockhart, for the simple reason that there was no contact.

“What I’d like to know,” said Smith, “is exactly how we’re going to deal with the gas.”

Lockhart noticed Smith’s use of the word “we.” It was a good sign, an excellent sign.

“I’m glad you asked me that,” said Lockhart. “Because some of us are going to pick it up tomorrow morning.”

“Pick what up?”

“All in good time, Smith, all in good time.”