2070-71: Nearly six decades after the discovery of the changer, which for the first time made it possible to commute between parallel worlds, a new posthuman society is flourishing on Langen Erde. But it gets into turmoil when a mysterious message comes in from the center of the galaxy: Join us. The superintelligent Next discover in this the blueprints for an artificial intelligence of huge proportions. Once built, the computer could not only change the position of the Long Earth in the cosmos forever, but also give an answer to the question of all questions: What is the meaning of life? But nobody knows the sender of the message, and no one knows if his intentions are peaceful.