“Give me the pipe.” He clawed his hand around it and started forward, poking the dead things aside. When he’d cleared an area and batted any rats away from the open water, he stepped into it. Madeleine stood on the backs of his heels and shivered, reciting the rosary prayer under her breath.

The lifts, half submerged, stood dark and empty. Water was welling out of them, making black bulges that oozed like oil.

“Nearly there.”

She stared at him, wild-eyed, and started again, “Hail Mary full of grace…”

The door at the side of the lift shaft was wedged open. The back of a chair peaked from the surface like an iceberg. Petrovitch propped the door wider with his foot and checked that there was no one on the stairs waiting for them.

“It’s quiet. Go.”

Madeleine pushed the chair further in and climbed up the first few steps. She had a tidemark of oil and slime around her hips, and her long legs were coated in dark ooze.

“That was disgusting,” she whispered.

Petrovitch stepped inside the stairwell and eased the door slowly back so that it wouldn’t bang, then he walked up to join her, water cascading from his coat. “I would say I’ve seen and done worse, but I can’t.”

“If I’d been on my own, I could never have done it.”

“Yeah. Know the feeling.” He sat down and lifted his feet above horizontal. Sludge dribbled out of his boots. “We’ve still got fifty floors to go. All the way to the top.”

Above them they heard the long echo of a closing door.

“All the way?”

“Every step.” He looked up, imagining the height of the staircase as it spiraled around the core of the building. “And we have to get to the Jihad before anyone else does.”

She held out her hand, and Petrovitch slapped the pipe into her palm.

“Thanks, but that’s not what I meant.”

“Oh. Okay.” He looked at both his hands, and picked the one without the missing digit. She laced her fingers through his, and they started to climb.

At floor ten—Petrovitch knew because he was counting, not relying on being able to interpret the kanji script—they were confronted by solid fire doors. The springs that held them shut were fierce, and these were what they’d heard banging from the ground floor.

“We do this quietly,” said Madeleine. She raised the pipe and pushed her shoulder against the crack in the double doors. There was a puff of air, the soft sigh of a seal being broken. She waved Petrovitch on, then let the door slowly ease back.

He went a little way on and listened intently. He thought he could make out two sets of footsteps. They sounded weary, grudging. He supposed his sounded the same.