On an unremarkable day, a diagram of a mysterious device appears on the Internet, by assembling which anyone can move from our Earth to countless of its variations. Consequences? They come immediately. Mass migration of people to nearby and distant worlds leads to the collapse of economies and the devastation of cities. But not all people need a device to move around the worlds, and young Joshua is one of them. A large corporation hires him to explore newly discovered worlds and, together with an artificial intelligence that claims to be the reincarnation of a Tibetan mechanic, he sets off on a long journey. In the vastness of new worlds, he will have to find not only intelligent life, but also face the threat of extinction of all humanity.