In the far future, war has devastated the entire Earth, leaving behind only a barren wasteland where the water supply is controlled by a greedy king. In search of a long-lost lake, Sheriff Rao asks the demon king for help... and receives the king's son, Beelzebub, and his assistant, Thief. Together, this unlikely trio sets off across the desert, facing dragons, bandits, and the deadliest foe of all... the king's own army!