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.
Loki brings Jane Foster to Asgard and tries to convince Odin that it was Thor who brought her there. In order to prove which of his sons is lying, Odin sends both to Skornheim, where they must endure its deadly dangers.
Escaped convict Crusher Creel is given power by Loki to absorb the properties of anything that he touches. As the Absorbing Man, Creel uses his fantastic strength to battle Thor.
Loki lures a hunter into The Temple of Darkness, a hidden tomb where the hunter's spirit enters the body of the Indestructible Destroyer, an enchanted suit of armor forged by Odin.
Scientist Paul Duval gains the power to turn himself (and whoever he touches) into living stone. As the Grey Gargoyle, he attacks Thor hoping to steal Thor's magic hammer, which he believes will help him gain immortality.
Zarrko, the Tomorrow Man, travels back in time to 1962 to steal a cobalt bomb that he plans on using to make himself ruler of the 23rd century. Thor follows him forward to 2262 in order to defeat him.
When the Greek god Hercules arrives on Earth, he takes a fancy towards Thor's love Jane Foster. An enraged Thor fights it out with Hercules all over New York City.
Tricked into signing a contract to become the ruler of the underworld, Hercules must rely upon Thor to champion his cause and help him to win his freedom.
When a race of underground lava men threaten the surface world with destruction, Thor gathers his Avenger teammates in an attempt to thwart the attack. The group is aided by an unlikely ally, their former team member, the Incredible Hulk.
