The galaxy is divided between the gigantic and cooperative meta-civilization of Amalgam, and the mysterious, silent inhabitants of the galactic core, known as the "alienated". For a long time, the alienated suppressed any attempts by the Amalgam to penetrate their territory, but allowed travelers to make risky flights, moving along a route through the central galactic bulge. The cycle is somewhat arbitrary. The action of the story "Riding the Crocodile" takes place in the same world as in the novel "Incandescence", but 300,000 years before its events. Other stories are also not directly related to the events of the novel, but take place in the same universe.