In the very center of the Galaxy, the stars are going out one after another. This discovery, foreshadowing the death of the Universe, coincided with the appearance in the Solar System of a mysterious Object that did not respond to the attempt at contact. The Argo starship rushes after him. The meeting of the astronauts with a gigantic alien structure floating among the stars, the penetration of earthlings into the Time Station and communication with the artificial intelligence that created it, help prevent a cosmic catastrophe and become the beginning of the stellar Expansion of humanity.