“Yes,” I said, “but what are the actual mechanics, if that isn’t too crude a word. How do we cooperate with each other! Be specific with me. I don’t believe this can be done.”

“Oh, come now, of course you do,” he suggested gently, as if he were a patient teacher. It seemed almost an impersonation of David, without David’s vigor. “How else would I have managed to take ownership of this body?” He made a little illustrative gesture as he continued. “We will meet at an appropriate place. Then we will rise out of our bodies, which you know very well how to do and have so eloquently described in your writing, and then we will take possession of each other’s bodies. There’s nothing to it really, except complete courage and an act of will.” He lifted the cup, his hand trembling violently, and he drank a mouthful of the hot coffee. “For you, the test will be the courage, nothing more.”

“What will keep me anchored in the new body?”

“There’ll be no one in there, Monsieur de Lioncourt, to push you out. This is entirely different from possession, you understand. Oh, possession is a battle. When you enter into this body, there will be not the slightest resistance from it. You can remain until you choose to disengage.”

“It’s too puzzling!” I said, with obvious annoyance. “I know reams have been written on these questions, but something doesn’t quite … ”

“Let me try to put it in perspective,” he said, voice hushed and almost exquisitely accommodating. “We’re dealing here with science, but it is science which has not yet been fully codified by scientific minds. What we have are the memoirs of poets and occult adventurers, quite incapable of anatomizing what takes place.”

“Exactly. As you pointed out, I’ve done it myself, traveled out of the body. Yet I don’t know what takes place. Why doesn’t the body die when one leaves it? I don’t understand.”

“The soul has more than one part, as does the brain. Surely you know that a child can be born without a cerebellum, yet the body can live if it has what is called the brain stem.”

“Dreadful thought.”

“Happens all the time, I assure you. Victims of accidents in which the brain is damaged irretrievably can still breathe and even yawn in their slumber, as the lower brain carries on.”

“And you can possess such bodies?”

“Oh, no, I need a healthy brain in order to take full possession, absolutely must have all those cells in good working order and able to lock into the invading mind. Mark my words, Monsieur de Lioncourt. Brain is not mind. But again, we are not talking of possession, but of something infinitely finer than that. Allow me to continue, please.”

“Go ahead.”

“As I was saying, the soul has more than one part, in the same manner as the brain. The larger part of it—identity, personality, consciousness, if you will—this is what springs loose and travels; but a small residual soul remains. It keeps the vacant body animate, so to speak, for otherwise vacancy would mean death, of course.”