What does it mean to be human, and what happens when humanity takes the next step in its evolution?   When Join arrived, it was hailed as a miracle: a technology that allowed humans to join consciousnesses. To experience perfect, constant companionship through multiple bodies. To never die.   But Chance and Leap—two joins of five and four respectively—discover a terrifying malfunction in the technology.   Chance and Leap must journey into the climate change–ruined heart of North America and the communities of never-joined “ferals” in search of the only ones who can dismantle the technology: the ones who created it.