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.