“I know it was pretty low,” Matthew said. His deep-set eyes looked shadowed. “I know that. But you know how I was then. It sounded like a good moneymaking scheme, one I could leave on the back burner, in case we ever needed it.”

“And your own baby was about to die because you hadn’t taken her to a doctor,” I said. “Or was she already dead when Chip called?”

“That’s where you got the different baby!” Mark said. I’d never seen so much emotion on his face. “Dad, why didn’t you tell me?”

Now it was Matthew’s turn to look confused. “You knew it wasn’t really Gracie?” he said to his son. “I never worried about you! You were hardly ever around. How’d you know?”

And all of a sudden, everything clicked into place.

“I know how,” I said. “Cameron told him. She didn’t know right away, any more than the rest of us did. It took her a while to figure it out. But when she did her senior biology project, she did it on eye color and genetics. You and my mom couldn’t have had a green-eyed child.”

Mark collapsed onto the couch. His legs simply gave out from under him. “Dad, she was going to call the police,” he said. “She was going to tell them you’d kidnapped a kid to take Gracie’s place, because Gracie had died.”

“It was you, Mark,” I said, feeling that my voice was coming from somewhere very far away. “It was you. You picked her up when she was on her way back from school. You told her—what did you tell her?”

“I told her that you’d had an accident,” he said. “I was on my motorbike that day, so I told her to leave the backpack by the road. She didn’t ask any questions. She got on. I went toward the hospital, but I pulled off at an empty gas station because I told her something was wrong with my bike. I told her to go around back to see if there was an air pump. I went after her.”

“How did you do it?” I said, very quietly.

He looked up at me with an expression I hope I never see again. He was ashamed, he was horrified, and he was pleased. “I choked her to death,” he said. “I have big hands, and she was so small. It didn’t take long. I had to leave her there, because I couldn’t get her back on the bike. I went later, with Dad’s truck. I wanted to leave her there, but I was afraid you’d find her, you freak.”

My head swam and I sat abruptly on the armchair. Tolliver hit Mark with everything he had, and Mark collapsed sideways, bleeding from the mouth. Matthew was standing exactly where he’d been, his mouth literally hanging open.