At the beginning of the year 426 New Galactic Calendar, the fate of humanity is at stake. In the defensive struggle against the hostile superintelligence Seth-Apophis, Terra has found itself caught in the crossfire. The last Porleyters, members of a long-forgotten people, have now gained control over Earth. Perry Rhodan embarks on a rescue mission, following a clue to the Ring of the Cosmocrats - an ancient artifact of the Porleyters that is meant to help him end this confrontation. Millions of light-years away from the Milky Way, Rhodan makes a discovery. There, he also encounters the Stone Messenger, a simple rock from the domain of Seth-Apophis, whose discovery reveals incredible truths.