The Death Gate Cycle is a seven-part series (heptalogy) of fantasy novels written by Margaret Weis and Tracy Hickman. The main conflict is between two powerful races, the Sartan and the Patryns, which branched off from humans following a nuclear/anti-matter holocaust. Centuries prior to the events of the series, the Sartan attempted to end the conflict by sundering the Earth into four elemental realms, and imprisoning the Patryns in a fifth prison world, the Labyrinth.