Twenty-five years ago, an unknown person raced across the pier in Kühlungsborn, sank into the waves, and has been considered missing ever since. But then, a confused-sounding individual calls the police emergency number and claims to have killed not only themselves but also three other people. David Lux, a restless retired police reporter with strong connections to the homicide department, begins to investigate. The caller turns out to be a being that can disguise itself like a chameleon. Lux has no idea that both he and his best friend, Chief Inspector Karl Delgado, are themselves on the "Black Moth's" death list...