Reluctantly, Cal stopped pummeling.

They watched as Spencer, wheezing and bleeding, rolled over and crawled away on all fours. He shoved through the door at the end of the bays and disappeared.

Cal noticed a crutch on the ground. He picked it up and headed after him.

“Cal,” said Johnny Boy. But Cal was gone.

In the corridor, Cal saw Spencer struggling with the fire escape door. He ran up and Babe Ruthed the gunshot wound on Spencer’s thigh with the crutch.

Spencer heard someone scream. He didn’t realize it was him. He felt himself get lifted and then his head used like a battering ram. Dazzling sunlight blinded him. He flew through the air to the sound of Cal’s delighted laughter and lost consciousness.

Scott looked at the back doors. Bullets would have no trouble penetrating them. Whoever was outside would know that too.

There was another knock. “I know you’re in there, Detective.”

Spencer crawled across the trash- and rubble-strewn vacant lot. His head was swimming in the heat and when he coughed, blood speckled the ground. He reached a chain-link fence and used it to pull himself upright. Working his way along, he found a hole. He lay back down in the filth and slithered through. His right leg felt numb and virtually useless, but he had to keep moving.

“What am I looking at?” asked Scott, holding the plastic sandwich bag in front of his face.

“That’s a digital signature machine in there,” said Chris. “Those things that couriers use. But this is a very special one.”

“Enlighten me.”

“It’s an AtoB signature box. We both know that’s the courier company McGrath’s outfit uses to launder. This thing has got four signatures on it from McGrath’s accountant guy, Cal, with his prints. And those four numbers he’s signed against, their total matches the amount stolen.”

“What does this do for me?”

Chris shrugged. “If McGrath knew you had this, he’d kill Cal for sure. That’s leverage, Detective.”

“Where’s Burnham?”

“Forget Burnham. Did you really think a drunk, certified hopeless dad would get them to incriminate themselves on tape so you could swoop in and clean up? The big crime show spectacular thing? This is about you getting McGrath.”

“What about the money they stole? I’m supposed to just write that off?”

“Detroit writes off other people’s money all the time. The place is known for it. Anyway, move fast and then it’ll be McGrath wanting to make a deal to spend the last few years of his life out of jail. And what’ll he have to bargain with?”

“I, uh, you realize they killed a cop? And you’re giving me . . . What the fuck are you giving me?”