After years of imprisonment in Asgard, Loki escapes to Earth to gain his revenge on his half-brother, Thor. Once there, Loki learns that Thor lives among humans as one of them, Dr. Donald Blake.

Loki enhances the mental powers of Sandu, a carnival mystic. Sandu then uses his supernatural powers of levitation to battle Thor and to trap him beneath an entire building.

Hoping to break up the love between Thor and Jane Foster, Odin heeds advice from Loki. Loki uses this opportunity to pit the Enchantress, the Executioner, and two powerful giants against Thor.