He looks at me carefully over his glasses. “In a way,” he says. “It’s a long therapeutic process, which can take years. Some practitioners think it is the best solution. I don’t know. To merge fully evolved personalities into one another might be difficult—inadvisable. Some consider these personalities, these alters, to be people in their own right. They have lives, thoughts. For want of a better word, they have souls. It would be like trying to merge you and me.”

“But it can be done,” I say.

“Ted,” he says. “If you know—someone—with this condition, they are going to need help with this. A lot of help. I could guide her…”

His left hand rests in his lap. His right hand lies palm down on the small table at his side, an inch or so from his mobile phone. I pick up a pen from the table and play with it, watching his right hand, the one near the phone, very carefully. I wait for him to make the next mental leap. I wait for him to reach for the phone. I hope he doesn’t. Strangely, I have grown fond of him.

“Such a rich puzzle,” he says dreamily, and I can tell that he’s not really talking to me anymore. “It’s a question I ask in my book. Of what does the self consist? You know, there is a philosophical argument that DID could hold the secret to existence. It theorizes that each living thing and object, each stone and blade of grass, has a soul, and all these souls together form a single consciousness. Every single thing is a living, component part of a breathing, sentient universe … In that sense we are all alternate personalities—of God, essentially. Isn’t that an idea?”

“Neat,” I say. “Could you give me the names of those books, please?” I am as polite as possible. “About the integration thing.”

“Oh—sure.” He tears a page out of his notebook and scribbles.

“Please think about it, Ted,” he says, eyes on the page. “I think it could be really helpful if I could talk to her.” His eyes are full of safe abstractions. He is lit up with the thrill of it. I keep the pen hidden in my fist, held like a dagger.

If only he knew. I think of the dark nights with Lauren, the clinging moistness of her hands, her sharp teeth and nails, which leave neat scores in my flesh. I think of Mommy.