Somewhere at the edge of known space is the Great Void. That inscrutable, shapeless, ever-changing place is where the expanding universe springs forth, where new planets and new life forms are created. It's also, according to the gods of Hypsis, the place where Galaxity's Earth was sent and is being kept prisoner. Valerian and Laureline begin a discreet investigation, but it doesn't take long before they start finding obstacles in their path, placed by the rulers of Rubanis – and their mysterious master...