“Finally,” Agent Locke said, turning around to face me, “it’s just us girls.”

I took a step forward, toward Michael, toward Dean, but Agent Locke waved her gun at me. “Nuh-uh-uh,” she said, making a tsking sound under her breath. “You stay right there. We’re going to have to have a little talk about following orders. I told you not to do anything stupid. Letting Michael trail you here was stupid. It was sloppy.”

One second she was standing there, looking exactly like the woman I knew, full of life, a force of nature who was very good at getting her own way, and the next she was on top of me. I saw a blur of silver and heard the impact of her gun with my cheekbone.

Pain exploded in my face a second later. I was on the floor. I could taste blood in my mouth.

“Stand up.” Her voice was brisk, but there was an edge to it I’d never heard before. “Stand up.”

I clambered to my feet. She took her left hand and placed her fingers under my chin. She angled my face upward. There was blood on my lips. I could feel my eye swelling shut, and even the slight movement of my head sent stars into my eyes.

“I told you not to do anything stupid. I told you I’d make you regret it if you did.” Her fingernails dug into the skin under my chin, and I thought about the victims’ photos, the way she’d peeled the skin from their faces.

The knife.

“Don’t do anything else that I’ll be forced to make you regret,” she said coldly. “You’ll only be hurting yourself.”

I looked into her eyes, and I wondered how I could have missed this, how I could have spent all day, every day with her for weeks without realizing that there was something wrong with her.

“Why?” I should have kept my mouth shut. I should have been looking for a way out, but there wasn’t one, and I needed to know.

Locke ignored my question and glanced at Michael. “It’s a pity,” she said. “I’d hoped to spare him. He has a very valuable gift, and he certainly took a shine to you. They all did.”

With no warning whatsoever, she hit me again. This time, she caught me before I fell.

“You’re just like your mother,” she said. And then she tightened her grip on my arm, forcing me to stand straight. “Don’t be weak. You’re better than that. We’re better than that, and I won’t have you sniveling on the floor like some common whore. Do you understand me?”

I understood that the words she was saying were things that someone had probably once said to her. I understood that if I asked her how she knew my mother, she’d hit me again and again.

I understood that I might not get back up.

“I expect an answer when I talk to you, Cassie. You weren’t raised in a barn.”

“I understand,” I said, filing away her choice of words, the almost maternal undertone to her words. I’d assumed that the UNSUB was male. I’d assumed that when the UNSUB killed females, there might be some kind of underlying sexual motivation. But Agent Locke was the one who’d taught me that when you changed one assumption, you changed everything.

You’ll always be wrong about something. You’ll always miss something. What if the UNSUB is older than you thought? What if he is a she?

She’d practically told me that she was the UNSUB, and it had gone right over my head, because I’d trusted her, because if the UNSUB’s motivation wasn’t sexual, if he wasn’t killing his wife or his mother or a girl who turned him down, over and over again, if he was a she …

“Okay, kiddo, let’s get this show on the road.” Locke sounded so much like herself, so normal, that it was hard to remember she was holding a gun. “I’ve got a present for you. I’m going to go get it. If you move while I’m gone, if you so much as blink, I’ll put a bullet in your knee, beat you within an inch of your life, and put a matching bullet in lover boy’s head.”

She gestured toward Dean. He was unconscious, but alive. And Michael …

I couldn’t even look at Michael’s body, lying prone on the floor.

“I won’t move.”

She was only gone for seconds. I took a single step toward Michael’s abandoned gun and froze, because I knew our captor was telling the truth. She’d kill Dean. She’d hurt me.

Even a moment’s hesitation was too long, and an instant later, Locke was back—and she wasn’t alone.

“Please don’t hurt me. Please. My dad has money. He’ll give you whatever you want, just please don’t—”

It took me a moment to recognize Genevieve Ridgerton. There were ugly cuts on her neck and shoulders. Her face was swollen beyond recognition, and there was blood crusted on her scalp. The skin around her mouth was pink, like someone had just ripped off a strip of tape. She made a mewling sound, halfway between a gargle of water and a moan.

“I told you once,” Agent Locke said to me, knife in hand and a wide smile growing on her face, “that I was only ever a Natural at one thing.”

I struggled to remember the exchange, one of the first things she’d ever said to me, a mischievous gleam in her eyes. I’d assumed she was referring to sex—but the helpless, hopeless expression in Genevieve’s eyes left very little doubt what Locke’s so-called gift was.

Torture.

Mutilation.

Death.

She considered herself a Natural killer, and she was waiting for me to say something. Waiting for me to compliment her work.

You knew my mother. You hit me, you hurt me, you told me it was my fault. You were almost certainly abused as a child. You called me kiddo. I’m not like your other victims. You sent me presents. You groomed me.

“The first day we met,” I said, hoping the expression on my face looked earnest enough, innocent enough to please her, “when you said you were a Natural at only one thing, you also said that you couldn’t tell me about it until I was twenty-one.”

Locke looked genuinely pleased that I remembered. “That was before I knew you,” she said. “Before I realized how very like me you were. I knew you were Lorelai’s daughter. Of course I knew—I was the one who flagged you in the system. I spoon-fed you to Briggs. I brought you here, because you were Lorelai’s, but once I started working with you …” Her eyes were alight with a strange glow, like a blushing bride’s or a pregnant lady’s, brimming with happiness from the inside out. “You were mine, Cassie. You belonged with me. I thought I could wait until you were older, until you were ready, but you’re ready now.”

She pushed Genevieve roughly down to her knees. The girl collapsed, her body shaking, the taste of her terror potent in the air. Locke saw me looking at Genevieve, and she smiled.

“I got her for you.”

Gun still in her right hand, Locke held her knife out to me with her left, hilt first. The look in her eyes was hopeful, vulnerable, hungry.

You want something from me.

Locke didn’t want to kill me—or maybe she did, but she wanted this more. She wanted me to take the knife. She wanted me to slit Genevieve’s throat. She wanted me to be her protégé in more ways than one.

“Take the knife.”

I took the knife. I eyed the gun, still in her hands, trained on my forehead.

“Is that really necessary?” I asked, trying to act as though the thought of turning this knife against the sobbing girl on the floor didn’t make me want to throw up. “If I’m going to do this, I want it to be mine.”

I was speaking her language, telling her what she wanted to hear: that I was like her, that we were the same, that I understood that this was about anger and control and having the power to decide who lived and who died. Slowly, Locke lowered the gun, but she didn’t put it down. I measured the distance between us, wondering if I could sink the knife into her before she could get a shot off at me.

She was stronger than I was. She was better trained. She was a killer.

Stalling for time, I knelt next to Genevieve. I bent down, bringing my lips to her ear, letting the expression on my face take on a hint of the madness I saw in Locke’s. Then, my voice so low that only Genevieve could hear me, I whispered to the girl, “I’m not going to hurt you. I’m going to get you out of here.”