They came from another world to battle for Earth - now a hero must fight to save us all. Loki of the underworld, is defeated on the battlefield by Thor and brought to Odin for justice. But Loki escapes to Earth, where he will conquer mankind and raise an even larger army to use in his quest for domination throughout the Nine Realms. Thor pursues Loki, but in the journey, he is rendered defenceless, awakening on Earth without his mighty hammer, or his memory. Alone and disoriented, Thor enlists the help of a female human companion and fights his way North, in search of his mythical weapon. Finding his hammer, Thor's identity and prowess are restored and he prepares himself for a final climactic battle with Loki, to prevent the overthrow of the universe.