I moved a rook into position to counter the bishop.

Cilia shook her head to dislodge the black memories and sipped a generous portion of her drink before removing her bishop to its original position. I sent another pawn forward.

“I was not weak,” she said, and moved a pawn to match mine. “Shortly after my mother’s death, I went to my father’s bed. I crawled in next to him—he seemed to like that—and I gently placed the blade of a ten-inch-long butcher knife I had spent fifteen minutes sharpening against his throat and assured him that if he did not leave me alone I would kill him. I spoke calmly, Mr. McKenzie. Softly, almost in a whisper. I think that’s why he didn’t believe me. He shouted at me, insulted me, told me to get out of his bed. I didn’t move. But the knife blade did. It moved about an inch across his throat.

“The cut wasn’t deep, but there was a great deal of blood. It spilled down his neck and onto the pillow and sheets. He clutched his throat to stem the bleeding. ‘You’re crazy,’ he told me. ‘You’re insane.’ But now he believed. I told him to leave me alone, to leave Robert alone. He said he would. He kept his promise. He never forced himself on me again. Nor did he ever again engage me in a conversation that lasted more than thirty seconds. He made it clear that I would need to fend for myself—myself and my brother. It was because of my brother that I stayed in the house even after I reached my majority. It’s your move, Mr. McKenzie.”

I was astonished. Not only at the story, but also at the matter-of-fact manner in which Cilia related it. She spoke about subjects that would send most people into an emotional frenzy, yet her voice held no anger or pain. Instead, it possessed a yearning, thoughtful quality, and when she spoke, she had a way of drawing out some words as if she wished she could think of better ones.

I moved my rook, and Cilia swept it off the board.

“Pay attention, McKenzie,” she said.

“Tell me about Becker.”

“In due time. First, allow me to tell you about my brother. Robert was an alcoholic, like our father, and like our father, he was abusive and totally amoral. Merodie wasn’t the first young woman he corrupted by any means. If there was a difference between the two, it was that Father was also ambitious. He enjoyed money and power and wasn’t above working long, hard hours to accumulate them. Robert did mind. He detested work, school, anything that required effort. Robert lived only to indulge himself.

“Make no mistake, my father adored Robert. At the same time, he was fearful of what Robert would do to the company he built from scratch. So he turned to me. I had a master’s degree in chemistry. My father offered me a job in the company’s R&D department and paid me nearly twice as much as everyone else with similar credentials and years of experience. A number of times I was invited to business functions and other gatherings. We rarely spoke at these events, yet he would introduce me to one and all as his ‘favorite daughter.’ That was as close as he ever came to saying, ‘I’m sorry.’ Later, after he died, my father left his entire estate—his business and the money to run it—to me. I was as surprised as anyone. For a time I amused myself with the delusion that he had a guilty conscience, but time taught me that he left everything to me because he did not trust Robert. I was all he had left.

“Now, this is important, Mr. McKenzie. When I first joined the firm, St. Ana Medical was attempting to develop a product that could compete with Ativan, Valium, and Xanax as a viable treatment for insomnia and anxiety. I was working on an analog of gamma-hydroxybutyrate—”

“GHB?”

“Yes.”

“The date-rape drug?”

“Yes. GHB had been used productively in Europe as an anesthetic, as an aid to childbirth, and as a means to treat sleep disorders such as narcolepsy. We were hoping to develop a superior analog. And I succeeded.

“As a sleep aid—and this is GHB’s primary disadvantage—as a sleep aid GHB has only a short-term influence. Even though sleep is deeper and more restful, people will wake up after only about three hours. This pattern is known as ‘the dawn effect.’ However, with my analog, people remained asleep for eight to nine hours. Something just as significant—while GHB can be detected in urine four to five hours after it is taken, my analog completely metabolized into carbon dioxide and water in less than two hours.

“Unfortunately, it was at about that time that GHB was banned in the United States by the FDA and later designated a Schedule I Controlled Substance because people, mostly men, used it to assist in sexual assault, mostly of women. As a result, my analog was shelved.”

“Why is that important?” I asked.

“The analog allowed me to kill without detection.”

“Kill who?”

“My father, to begin with.”