The third part of the “Galaxies” series. The expedition from Nore is successfully transported to the At Lanta galaxy to colonize one of its planets. Having landed on the planet, earthlings suddenly learn that some highly developed civilization has already visited it and, for some unknown reason, left it. Trying to find out the reason for the departure of an alien civilization, earthlings organize several expeditions to one of the planet’s caves, where they encounter local humanoids who are already using bows and spears for their hunting. An attempt to make contact with them ends in armed confrontation. Local humanoids attack a colony of earthlings, but the colonists manage to defend their right to colonize the planet and ultimately unravel the mystery of their new abode.