“Perhaps if you got hold of the formula, I might be able to help you.”

Lockhart shook his head.

“No, sorry, Ted, there’s no time for that. If the Germans are going to use it, they’re going to use it soon. Please, think.”

This was followed by a lot more head-scratching.

“Well…actually…no,” said Barham. “No, it’s ridiculous.”

“What? Tell me.”

“I suppose you could try blowing it up.”

“But surely that would release the gas?”

“Not if you blew it up in a chamber. You’d need something pretty heavy-duty, but it would probably work….”

Ted was speaking quickly now.

“We can safely assume that the sarin is stored in liquid form, because it’s much more stable to store poison gas in that way. That’ll mean that it’s kept in highly pressurized containers, which would presumably be mounted on your rockets….”

“How big would these containers be?”

More scratching.

“Well, if this sarin is so bloody deadly, you wouldn’t need very much of it, would you? I’d guess that each container wouldn’t be much larger than a half-bottle of wine.”

“What then?”

“Simple. You place all your containers in your chamber, put a small amount of explosive in it, seal it, and then detonate it. Bingo!”

“How much explosive, Test Tube?”

“Ooh—I’d say no more than a pound of dynamite. That would easily do the trick, going off in an enclosed space. We don’t of course know how many containers there are, but I’d say that if you used, I don’t know, something the size of a normal fifty-gallon oil drum, you’d be able to blow up at least a hundred and fifty to two hundred containers at a time. The residue in the chamber would be pretty ghastly stuff, but it would be relatively harmless and unusable. This is all hypothesis, of course.”

“So could I use a normal oil drum?”

Barham started laughing.

“Good God, no! That would simply blow apart! You need something that can take the pressure.”

“What, then?”

“Well, it would have to be immensely strong. Be able to take a lot of force.”

“Where am I going to get that?”

Barham turned his palms up.

“That’s your problem. Try a factory.”

“Will you join me, Test Tube?”

“Sorry, John, I can’t.”

“Why not? You’d be an enormous help.”

“I can’t. I’d be useless. Anyway, I’m needed here.”

“What for?”

“I’m making some smoke bombs. We’re organizing a mass breakout, and we want to cause as much confusion as possible.”

Lockhart was nearly speechless. All he could say was “good luck.” He expected this would be the last time he saw Test Tube. He couldn’t imagine both of them surviving the war.