In the far future, war has destroyed the entire Earth, leaving behind a barren wasteland where the water supply is controlled by a greedy king. Searching for 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 army itself!