XLI century. Humanity has conquered most of the galaxy, colonizing planets suitable for settlement, simultaneously destroying the indigenous population of less developed worlds. Commissar Major Andreevskikh, the leader of a peaceful expedition of colonizers on the planet Lentis-2, is recalled to Earth to carry out a dangerous mission - to find out the reasons for the loss of contact with the research cruiser Progress. During the officer’s absence from his homeland, a lot has changed - the citizens of Earth live in constant fear of the terrorist organization Union for the Freedom of Alien Worlds, which condemns the government’s aggressive policies, and the major immediately becomes a target for radicals, as a person directly involved in colonization. Despite the threat to life, Andreevskikh and a platoon of paratroopers are sent to Progress.