“Just that it was terrible,” he said. “You don’t see many like that, and you don’t want to. Once in a lifetime is enough.”

“Nothing else? Nothing strange?”

“I suppose,” Maybrick said, “there was one odd thing. When we found Newman, he was holding a Walkman.”

“A what?” Callum said.

“You’re too young for that, I suppose,” he said. “A Sony Walkman. A music player. Used to be the thing. Played tape cassettes. He wasn’t just holding it—he was clutching it tight to his body. Strange thing to be clutching during a drugs bust or a mass shooting, at any rate.”

Stephen’s expression changed instantly. His eyebrows rose so much, they seemed to drag his entire face along for the ride.

“That means something to you?” the sergeant asked. “What’s going on here? I deserve to know. I’ve got a lot of people out on the street tonight looking for this bastard.”

“Thank you,” Stephen said. The deep, serious voice was dropped. This was normal Stephen. In fact, there was a shake in his voice. “That’ll be all.”

There weren’t a lot of options for places to huddle at three in the morning on Ripper night, so we sat in the police car a few streets over, the engine idling.

“I’m not sure what we just learned,” Callum said. “I just know I feel sick.”

For once, I wasn’t the only one who was completely baffled and uninformed. Stephen had fixed his gaze straight ahead, at the back of a van.

“Stephen?” Callum said. “Tell me you aren’t thinking what I’m thinking. Please tell me that.”

“A Walkman,” Stephen said quietly. “Before mobile phones, that would have been the perfect device. Same idea. A common object that anyone could be seen carrying. A few buttons to push to send an electrical current through the stones. A Tube station used as an office. A body found clutching a Walkman. They weren’t undercovers—they were us. The squad wasn’t disbanded because of funding—it was disbanded because one of us went insane and murdered everyone else.”

Callum laughed darkly and dragged his hands over his face.

“A dead station,” he said. “For the dead police. That’s what they’re called, the disused ones. Dead stations.”

“He knows we exist,” Stephen went on, his gaze still fixed. “All the messages. Murdering people in front of cameras. He wanted to make sure we knew he was a ghost. He wanted to get our attention. He knows us. He’s one of us.”

“This seems like an ambush,” Callum said. “If you’re right, he wants us to go to the place where he murdered the entire previous squad. I’ve been in those tunnels and old stations. If you don’t know your way around, you’re in trouble.”