Dean’s father was a serial killer. While I was traveling the country with my mom, Dean had been living twenty yards away from the shack where his father tortured and killed at least a dozen women.

And Dean had never said a word to me: not when we were working our way through Locke’s puzzles and bouncing ideas off each other; not when he caught me swimming in the pool that first time; not after we’d kissed. He’d told me that spending time inside the minds of killers would ruin me, but hadn’t breathed a word about his past.

Suddenly, everything fell into place. The tone in Lia’s voice when she’d said the pictures on the stairwell were there for Dean’s benefit. The fact that Agent Briggs had gone to Dean for help on a case when he was twelve. Michael introducing Dean by telling me that he knew more about the ways that killers thought than just about anyone. Lia asking me, as a favor, not to say anything about these interviews to Dean. The Bad Seed.

I stood up and shoved the binder back into my bag. Michael said my name, but I ignored him. I was halfway back to the house before I’d even registered the fact that I was running.

What was I doing?

I didn’t have an answer to that question. And yet, I couldn’t turn around. I kept going until I reached the house. I climbed the stairs, heading for my room, but Dean was waiting for me at the top, like he’d known today would be the day.

“You’ve been reading the interviews,” he said.

“Yeah,” I replied softly. “I have.

“Did you start with Friedman?” Dean asked.

I nodded, waiting for him to name the awful unspoken something that hung in the air between us.

“That’s the guy with the panty hose, right? Did you get to the part where he talks about watching his older sister get dressed? Or what about that bit with the neighbor’s dog?”

I’d never heard Dean sound like this—so flippant and cruel.

“I don’t want to talk about Friedman,” I said.

“Right,” Dean replied. “You want to talk about my father. Did you read the whole interview? On day three, Briggs bribed him to talk about his childhood. You know what he bribed him with? Pictures of me. And when that didn’t work, pictures of them. The women he killed.”

“Dean—”

“What? Isn’t this what you wanted? To talk about it?”

“No,” I said. “I want to talk about you.”

“Me?” Dean couldn’t have sounded more incredulous if he’d tried. “What else is there to say?”

What was there to say?

“I don’t care.” My breath was still ragged from running. I was saying this wrong. “Your father—it doesn’t change who you are.”

“What I am,” he corrected. “And yes, it does. Why don’t you go ask Sloane what the statistics say about psychopathy and heredity? And then why don’t you ask her what they say about growing up in an environment where it’s the only thing you know.”

“I don’t care about the statistics,” I said. “We’re partners. We work together. You knew I was going to find out. You could have told me.”

“We’re not partners.”

The words hurt me—and he meant for them to.

“We won’t ever be partners,” Dean said, his voice razor sharp and unrepentant. “And do you want to know why? Because as good as you are at getting inside normal people’s heads, I don’t even have to work to get inside a killer’s. Doesn’t that bother you? Didn’t you ever notice how easy it was for me to be the monster when we were ‘working’ together?”

I’d noticed—but I’d attributed it to the fact that Dean had more experience at profiling killers. I hadn’t realized that that experience was firsthand.

“Did you know about your father?” I regretted the question the moment I asked it, but Dean didn’t bat an eye.

“No,” he said. “Not at first, but I should have.”

Not at first?

“I told you, Cassie. By the time Briggs started coming by with questions on cases, there was nothing left to ruin.”

“That’s not true, Dean.”

“My father was in prison. I was in foster care, and even back then, I knew that I wasn’t like the other kids. The way my mind worked, the things that made sense to me…” He turned his back on me. “I think you should go.”

“Go? Go where?”

“I. Don’t. Care.” He let out a shuddery breath. “Just leave me alone.”

“I don’t want to leave you alone.” And there it was, something I hadn’t even let myself think since Truth or Dare.

“How exactly was I supposed to tell you?” Dean asked, still facing away from me. “‘Hey, guess what? Your mom was murdered, and my dad is a killer.’”

“This isn’t about my mom.”

“What do you want me to say, Cassie?” Dean finally turned back around to face me. “Just tell me, and I’ll say it.”

“I just want you to talk to me.”

Dean’s fingers curled into fists at his sides. I could barely see his eyes behind the hair that fell in his face. “I don’t want to talk to you,” he said. “You’re better off with Michael.”

“Dean—”

A hand grabbed my shoulder and spun me around. Hard.

“He said he didn’t want to talk to you, Cassie.” Lia’s face was a mask of calm. Her tone was anything but. “Don’t turn back to look at him. Don’t say another word to him. Just go. And one more thing?” She leaned forward to whisper in my ear. “Remind me never to ask you for a favor again.”