Scouts who left Earth long before the first pharaohs of the Empire appeared on the planet return to the homeland of their ancestors and see that their place on the planet is occupied by a new civilization. Earthlings are alarmed by rumors that reflections in the most ordinary mirrors are becoming hazardous to health. And people suddenly start meeting their doubles on the streets. Imperial space scouts Neo Crassus and Bo Skir, the earthly girl Anna - a scientist hydrologist, and state security major Danilov look at the situation from different angles, but everyone sees behind the scenes of the events the same man in a gray hood, a mysterious type nicknamed the Joker. Perhaps he knows the answers to the questions, but how to find him?