The cruiser "Invincible" lands on the deserted and unremarkable planet Regis III. Life exists only in the ocean, for a reason unknown to people, never reaching land... The purpose of the expedition is to find out the circumstances of the disappearance of a starship a year ago on this planet, which did not make contact several hours after landing. The expedition discovers that there is a special life on the planet , born of the evolution of alien machines, which millions of years ago, by the will of fate, ended up on this planet.