My hand grew cold in his.

“You tested it on me?” I asked.

“I was a coward,” he said. “I let her convince me it was safe. We mapped your cognitive pathways.”

“Why?” I asked.

“To create a locked memory,” he said. “A secure vault inside your brain. I stored the encryption key in your subconscious.”

“I don’t remember any of this,” I said.

“Because we blocked it,” he said. “We used a chemical inhibitor to bury the memory. But the pathway is still there.”

“How do I unlock it?” I asked.

“The old house,” he said. “The stimulation unit is still in my study. You have to trigger the retrieval sequence.”

“Natalie,” Mara called out, her voice tense. “They’re at the end of the corridor. They’re setting up a breaching charge.”

“Hold them off,” I yelled back.

I looked back down at my father.

“Dad, what is the trigger?” I asked. “There has to be a word. A phrase.”

“The song,” he whispered. “The one your grandmother used to sing. The lullaby about the red boat.”

“I don’t know that song,” I said.