According to legend, the “Black Prince” is an extraterrestrial spacecraft that arrived from the depths of outer space in ancient times. Radars don’t see the satellite; it can be detected only against the illuminated side of the Earth—and not always. It changes its own orbit, and sometimes disappears for a long time. And one day, a cadet at a flight school, fascinated by cryptoastronomy, relying on myths and legends about the Black Prince, managed to calculate its location. He decides to find the object, and begins carrying out a bold plan. And what he finds turns humanity’s view of the question upside down: “Are we alone in the universe?”