Hayes Figueiredo is struggling to finish his documentary when handsome physicist Yusuf Hassan shows up, claiming Hayes is the key to understanding the Envisioner—a mysterious device that can predict the future. From a top-secret research facility run by the brilliant Dr. Kaori Nakamori, Hayes discovers he created the machine in a parallel universe—and he's married to Yusuf. But he doesn't recognize this other him, angry, aloof, and obsessive. Together, Hayes, Yusuf, and Kaori study the machine and all its secrets. When tragedy strikes, Hayes must do anything he can to save Yusuf's life. Because there are infinite realities, but only one Yusuf. With his heart, and the fate of the multiverse, in his hands, they tumble through a kaleidoscope of universes trying to save it all. But even escaping into infinity, Hayes is running out of space—soon he will have to decide how much he's willing to sacrifice to save the love of his life.