“There’s a possibility there may be booby traps,” he said. “If the rope goes slack, then you use it to haul me out. But under no circumstances are you to follow me in. Anything that is too much for me to handle will utterly destroy you—is that clear?”

“Crystal,” I said.

“There’s also a small chance that something other than me might try to escape out through here,” he said. “It may look somewhat like me, it may even be wearing my body, but I’m counting on you to know the difference. Understand?”

“And if that happens?”

“I’m counting on you to hold it back long enough for the others”—he nodded at the forensics team and other officers—“to escape. Hit it with everything you’ve got, but your best hope will probably be to try to bring the ceiling down on top of it.”

“Down on you, you mean.”

“It won’t be me,” said Nightingale. “So you needn’t worry about hurting my feelings.”

“That’s reassuring,” I said. “Assuming I survive my heroic rearguard action, what then?”

Nightingale gave me a delighted grin. “Remember the vampire nest in Purley?”

We’d bunged a couple of white phosphorous grenades into the basement where the vampires had been living, or undeading, or whatever it was they did. “How could I forget?”

“A similar procedure to that,” said Nightingale. “Only on a larger scale.”

“And after that?”

“That really won’t be my problem,” he said cheerfully. “Though you should go and see Postmartin as soon as you can.”

“Are you sure you’re up to this?” I asked. “If you have a relapse Dr. Walid will kill me.”

Just then the portable floods kicked in and filled the foyer with harsh light. Larry the Lark’s face was bleached as white as bone and the red stockings on the woman’s legs became the color of blood. Nightingale took a deep breath.

I turned to the people waiting by the floods. “Ladies and gentlemen, I strongly advise that you shut down any laptops, iPads, iPhones, airwave handsets—in fact anything that has a microprocessor. Shut it down and take the battery out.”

The forensics techs looked at me blankly. One of them asked why. It was a good question and I really didn’t have time to answer it. “We think there may be an experimental EMP device rigged farther in,” I said. “So just to be on the safe side …”

They weren’t really convinced, but there were probably enough weird rumors about Nightingale to make them all comply.

“What’s an EMP?” asked Nightingale.

“It’s complicated, sir,” I said.

“Tell me later then,” he said. “Everybody ready?”

Everybody was. Or at least said they were.