By the time the little girl wakes up on the altar, they’ve slammed your body against the wall. You don’t struggle as they chain your ankles and wrists.

The Pythia is judge. The Pythia is jury. Without order, there is chaos. Without order, there is pain.

I bolted for my room. With each step, my brain sank further and further into the Masters’ perspective. Laurel will never be safe. You’ll always find her. You made her, and hers is a glorious purpose. She is Nine, and the only way she leaves your custody is if you test her and she fails.

Nightshade had told me that the Masters didn’t kill children. But that hadn’t stopped them from leaving one of Laurel’s predecessors to die of thirst and heat exposure when he was six years old—just two years older than Laurel was now.

All must be tested. Nightshade’s prescriptive statement echoed in my memory. All must be found worthy.

If I had been a normal person, I might not have been able to imagine what kind of test these monsters might design for a child. But I could—I could imagine it in horrifying detail.

You won’t just hurt her. You’ll make her hurt someone else.

“Cassie?” Sloane stood in the doorway to our room, hovering outside it, like a force field kept her at bay.

“Did you figure it out?” I asked her. “The code?”

Sloane took a ragged breath. “I should have figured it out faster.”

“Sloane—”

“Seven isn’t just a number.” She didn’t let me tell her that this wasn’t her fault. “It’s a person.”

My heart thudded in my chest as I thought about the fact that my mother had almost certainly been the one to teach Laurel that song.

“Seven is a person,” I repeated. “One of the seven Masters.” My mouth was suddenly dry; my palms were sweating. Laurel had been safe, right up until the meeting where she’d passed on this information. “You know who he is?”

“I know who he was,” Sloane corrected. “E-flat, E-flat, E, A-flat, F-sharp, A, B-flat. Those aren’t just notes. They’re numbers.” She pulled a piece of paper out of her pocket. On it, she’d drawn an octave’s worth of piano keys. “If you sit down at the piano and you number the keys, starting with middle C…” She filled the numbers in.

“E-flat, E-flat, E…” I said. “Four, four, five?”

“Exactly,” Sloane said. “Seven notes translate into nine numbers—two digits each for A and B-flat. 445-97-1011.”

It took me a moment to make the connection between what Sloane was saying and the fact that she knew one of the Masters’ identities. “It’s a Social Security number.”

“That’s the thing,” Sloane replied. “It isn’t a Social Security number—or at least, it’s not anymore. I’ve been going in circles trying to figure out what else it could be, but then instead of cross-referencing it against current Social Security numbers, I decided to do a historical search.”

“How much of this required illegal hacking?” a voice asked from the doorway. I looked up to see Lia and, behind her, Michael and Dean.

“Almost all of it,” Sloane answered without skipping a beat. “When I went back a few decades, I found it. That Social Security number was given to a baby boy born in Gaither, Oklahoma, forty-three years ago. His name was Mason Kyle.”

I could barely hear my own thoughts over the pounding of my heart. “Mason Kyle,” I repeated.

“Why doesn’t Mason show up in the database now?” Lia asked. “Is he dead?”

“That’s the thing,” Sloane replied, sitting down next to me on the bed. “Other than the Social Security number, there is virtually no record of Mason Kyle ever having existed. No birth certificate. No death certificate. No employment history. Whoever wiped his record wiped it clean. The only reason I even found the Social Security number was that I hacked a decades-old archive.”

This was what Laurel had given us. This was what I’d risked her safety for. This was why she was back in their hands.

To become a Master, you have to leave your old life behind. You have to erase all traces of your prior self. You used to be Mason Kyle, I thought, addressing the words to a phantom, and now, you’re a ghost.

“That’s it?” I asked Sloane, my stomach heavy, a slight roaring in my ears.

“When I heard Laurel was missing, I kept looking,” Sloane said. “I looked and I looked and…” She bit her lip and then opened the tablet on her lap, angling it toward me. A picture of a young boy stared back at us. He was six, maybe seven years old. “This is Mason Kyle,” Sloane said, “circa thirty-seven years ago. It’s the one and only picture I was able to find.”

The photograph was faded and fuzzy, like it had been scanned in by someone who didn’t quite know how to work a scanner, but I could still make out most of the little boy’s features. He had dimples. A smile missing one of its front teeth.

He could have been anyone.

I should have left Laurel alone. Instead, I led them right to her. The implication that the Masters were watching us—that they could be anyone, anywhere—made me think of Daniel Redding’s chilling smile.

I wish I could be there to see what this group will do to you for coming after them.

“There’s software that does age progressions,” Sloane said softly. “If I can clean up the image and find the right parameters, we might be able to—”

I stood.

“Cassie?” Dean was the one who said my name. When he stepped toward me, I stepped back.

I didn’t deserve comfort right now. I thought of Agent Sterling saying that Scarlett Hawkins had been sacrificed on the altar of ambition. I thought of the promise I’d made Laurel.

I lied.

The backyard was pitch-black, except for the light from the pool. I’d come out here to be alone, but as I approached the water, it became apparent that I wasn’t the only one looking for refuge.

Celine Delacroix was swimming laps.

As I went closer, I saw that she’d turned on the black light. Like the rest of the house, the pool had been designed to facilitate our training. The outline of a body glowed at the bottom of the pool. Spatter patterns—visible only under the black light—marred the pool’s edge.