Outrageous and acclaimed, 26th-century musician Caran Watts depends on two secrets to stay alive: a dangerous drug that hides his illegal neurodivergence, and the help of an alien species whose vulnerable existence he has sworn to protect. But when he arrives in the Galilean system to tour his latest work, those secrets are hijacked by a powerful force to advance a genocidal plot. As fear infects Jupiter's moons, Caran must choose whether to keep hiding or risk both his own life and the lives of the aliens in hope of a better future.