After a series of adventures, Druuna discovers that the City is actually a giant spaceship which left Earth after an unspecified cataclysm and has drifted through space for centuries. At some point, Lewis, the ship's captain, delegated control to the computer Delta, which is responsible for creating the current state of affairs. (The Priests are actually androids operated by Delta.) Delta transformed Lewis into an immortal being, using organic parts from the healthy people who had been admitted to the upper levels of the City. Now, Lewis, tired of immortality, wants to die, which would eliminate Delta and destroy the City. This conflict is partially responsible for the gradual degradation of life on the ship/planetoid.