Phaeton, of Radamanthus House, is attending a glorious party at his family mansion, celebrating the thousand year anniversary of the High Transcendence. There he first meets an old man who accuses him of being an imposter, then an alien from Neptune who claims to be an old friend. The alien tells him that essential parts of his memory were removed and stored by the very government Phaeton believes to be wholly honourable. It shakes his faith. He is an exile from himself. Phaeton embarks upon a quest across the transformed solar system. Jupiter is now a second sun, Mars and Venus have been terraformed, and humanity has become immortal. Phaeton must search among humans, intelligent machines and bizarre life forms to recover his memory, and to learn what crime he planned to warrant such a pre-emptive punishment. His quest is to regain his true identity.