The Majipoor Cycle: Volume VI; The Prestimion Trilogy, Book II.

Prestimion should be jubilant. As the new Coronal Lord of Majipoor, the Starburst Crown is his at last. But the victorious lord is burdened with a great secret: he gained the throne through a bloody civil war -- a war no one remembers! With the aid of a phalanx of sorcerers, Prestimion dropped the awesome Spell of Oblivion over his people to heal his war-torn land. Forgotten now are the betrayals, the intrigues, and the slaughter. Only Prestimion and two of his surviving comrades-in-arms know anything happened at all.

Yet Prestimion must still account for his world's devastation and do the impossible: bring to justice the kinsman who languishes in the dungeon because no one can recall his unforgivable crime. And in his hour of triumph, Prestimion will face a threat to his kingdom far more insidious than war -- a twisted madness that cannot be controlled...