Months ago, Dean had shown me this. He’d tried to convince me to leave the Naturals program. He’d told me that murder and chaos wasn’t a language that anyone should want to speak.

Realizing that she wasn’t alone, Celine turned toward me, treading water. “No offense,” she said, “but you all really suck at hiding the fact that you work for the FBI.”

This girl was Michael’s sister. She was safe here. But if she hung around, she might not be for long.

“You should leave,” I told her. “Go back to school.”

Celine swam to the edge and pulled herself out of the pool, the water clinging to her body. She had to have been freezing, but didn’t shiver. “I’ve never excelled at should.”

I’d heard Michael say the same thing—more than once.

“Are you okay?” Celine asked.

“No.” I didn’t bother elaborating and turned the question around on her. “Are you?”

She sat down next to the pool, allowing her legs to dangle in the water, tilting her head back toward the sky. “I’m trying this new thing,” she told me. “Ultimate honesty. No more secrets. No more lies.” This was the girl from the painting—the one who painted her self-portrait with a knife. “So, in answer to your question, Cassie, I’m not okay. I am incredibly and quite possibly irreversibly screwed-up. That’s what happens when you figure out at the ripe old age of seven that your father isn’t your father—and that his best friend is. That’s what happens when, at the age of fourteen, your mother drunkenly admits to your biological father that you’re his. And that’s what happens when said biological father finally figures out that you know and corners you in your own studio to tell you that your dad—the man who raised you, his business partner and supposed friend—ruined you. That you would be so much more if he’d been the one in control. That, if he’d had the chance, he could have stamped the bad blood out of you when you were young, just like he did for his son.”

Bad blood. I could imagine Thatcher Townsend saying the words, could imagine him beating out of Michael the weaknesses he saw in himself. And then I thought of Laurel—the way she was being raised, the things she was expected to do.

The blood belongs to the Pythia. The blood belongs to Nine.

“How did you find out?” I asked, my voice hoarse, trying to concentrate on the present and not what my actions had cost the one person in this world that I’d sworn to protect. “When you were seven, how did you find out that Thatcher Townsend was your father?”

“I looked at his face,” Celine said simply. “And I looked at my own—not just the features, not my eyes or my lips or my nose, but the basic underlying facial structure. The bones.”

I searched Celine’s face for a resemblance to Michael’s father, but I couldn’t see it.

Celine must have sensed some skepticism. “I never forget a face. I can take one look at a person and know exactly what their facial bones look like underneath the skin. Creepy, I know, but what can I say?” She shrugged. “I’m a natural.”

My breath caught in my throat. Celine didn’t know the details of the program—why the FBI had brought us here, what we could do. She didn’t know what it meant to be a Natural, capital N. But I thought of Michael saying that ever since they were kids, she’d only drawn faces, of the digital photo she’d created of her and Michael. She’d taken a photograph of them as kids, and she’d mentally fast-forwarded with stunning accuracy.

There’s software that does age progressions. Sloane’s statement echoed in my head, and I thought about the role that genes had played in making each of us Naturals what we were. Our environments had honed our gifts—but the seed had been there from the beginning.

And Celine was Michael’s sister.

“I meant it when I said you should leave,” I told Celine, my voice sandpaper-rough in my throat. “But before you do, I need a favor.”

The face that stared back at me from Celine’s drawing was one I recognized.

Nightshade.

The likeness Michael’s half sister had drawn was eerily accurate, down to the boyish expression on the murderer’s face.

Seven, I thought, my heart pounding viciously in my chest. Seven Masters, seven ways of killing. The progression went in a predictable order, starting with the Master who drowned his victims and culminating in poison. Nightshade is Seven.

Nightshade is Mason Kyle.

The part of me that had felt numb and hollow from the moment I’d realized that the Masters had Laurel began to crack, like ice under the force of a pick. In the past ten weeks, the FBI hadn’t been able to uncover anything about Nightshade’s background. Now we had his real name. We knew where he’d been born. And—most importantly—we knew that he’d tried very hard to bury that information.

You’re the one who brought Laurel to Vegas. You’re the one who told me where she was.

I felt like my gut had been ripped open, like everything inside of me was leaking out. The man in this drawing had killed Judd’s daughter. He’d stalked us, and when we’d caught him, he’d wrapped Laurel up for me in a tidy little bow. Why? Had he been instructed to do so? Had it all been part of some twisted game?

I found Agent Sterling in the kitchen sitting opposite Briggs. Her hands were folded on the table, inches from his. You won’t let yourself touch him. You won’t let him touch you.

She was the one who’d brought me to Laurel. She wouldn’t blame Briggs for this. She wouldn’t blame me. After Scarlett’s death, Agent Sterling had left the FBI—because she blamed herself.

“Celine Delacroix is a Natural.” I spoke up from the doorway. Right now, wallowing in guilt wasn’t a privilege any of us could afford. “She did an age progression of a photo Sloane found. Nightshade’s name is Mason Kyle. We can use that.” My voice broke, but I forced myself to continue talking. “We can use him.”

It took sixteen hours to set up the interview. On one side of the glass, Briggs and Sterling sat opposite Nightshade. On the other side, Dean, Michael, Lia, and I watched.

We’d left Sloane at home with Celine and Judd. The only adult on our side of the glass was Agent Sterling’s father.