“You explained to me theories about different realities. What if this is true for all of us, and we are unaware of these realities, in the same way we can’t hear a dog whistle or see ultraviolet light, but we know those sounds and sights are real? What if there are as many Garretts as there are Daphnes? What if reality is so complex that there are worlds upon worlds of alternate realities and alternate Carolines, Garretts, Daphnes, and Toms? What if there’s a Garrett who is running a rat experiment right now, and one who’s a physicist and one who is serving his country in Vietnam, but we have no access to these realities?” “Exactly,” I said. “What if?”