“The cart’s definitely his,” Sampson told me. “We just found this.”

He held up an evidence bag with my own smudged business card inside. It felt like a hard kick to the head. What a mess this was.

“There’s also visible blood spatter on the frame, and a sawed-off sledgehammer on the bottom rack. Presumably our murder weapon.”

“I’ve been thinking about this,” I said. “There’s a long underpass right by Lindholm. Homeless people sleep there all the time. That may be where he’s been hunting for his victims.”

“Maybe so,” John said. “But then why cart them all the way over here? I don’t get this at all. Why K Street?”

Not counting Kyle Craig’s fake-out with Anjali Patel, all three victims in this case had been left somewhere along K, each one near the intersection of a prime-numbered street — Twenty-third, Thirteenth, and now Seventeenth. With two incidents, it had been harder to see, but with three, the pattern popped right out. I wondered if the letter “K” represented something specific in mathematics, but I wasn’t sure. And, moreover, “The man’s insane, Sampson. That’s the one constant. We may not get very far looking for motive here.”

“Or for him,” John said, and thumbed over at the cart. “Whatever made him leave his stuff behind, something’s changed, Alex. I don’t know what it is, but I have a feeling we may never see this guy again. I think he’s history.”

Chapter 92

STANISLAW WAJDA BLINKED AWAKE. It was hard for him to see at first. A chiaroscuro of vague forms filled his vision. Then, slowly, things began to distinguish themselves. A wall. Concrete blocks. An old boiler on a cracked cement floor.

The last he remembered, he’d been in the park. Yes. The boy. Was it just last night?

“Hello,” someone said, and Stanislaw jumped. His heart lurched into a gallop as he suddenly knew enough to be scared.

A man was there. Dark hair. Vaguely familiar.

“Where am I?” said Stanislaw.

“Washington.”

“I mean —”

“I know what you mean.”

His hands were unbound, he realized. His feet, too. No chains, no handcuffs. He’d almost expected otherwise. He looked down and saw that he was sitting, half slumped, in an old wooden chair.

“Don’t get up,” the man said. “You’re still going to feel a little bit groggy.”

He’d seen this man’s face before. At the shelter. Yes. With the two black detectives. Yes. Yes.

“Are you the police?” he said. “Am I arrested?”

The man chuckled low, which was very odd indeed. “No, Professor. May I call you Stanislaw?”

Even as the situation began to take shape, none of it made any sense to him.

“How do you know my name?” he said.