As Dr. Don Blake walks down a rainy street, a policeman pulls up and tells him that the Commissioner needs to get in touch with Thor. Once out of sight, Don transforms into the God of Thunder and heads to police headquarters. Once there, Thor is told there has been a breakthrough in the Damocles case. A nervous Bennett Barlow informs the hero that Damocles is his brother Eric, a bully who dominated Ben for most of their lives, though as adults, Ben is a successful physicist and Eric had been out of touch for many years. Ben can only give Thor Eric’s last address….
At his hideout, Damocles rejoices in the completion of his flying Cobalt Cannon so he can finally get back at all his enemies. When his henchmen ask when they will be paid, the mastermind silences them with a concussion grenade. But he worries about being able to control them much longer….
Interlude: A convict sits in prison, plotting his escape. Soon the wall melts and explodes and a huge alien hand reaches in to take him to freedom….
When Thor and Bennett Barlow arrive at the old boarding house, they are met by Eric/Damocles who fires on them with the Cobalt-Cannon. Thor is able to deflect the blasts with Mjolnir but a wide-angle burst blows the Thunder God away and Damocles seizes the opportunity to escape. The henchmen persuade him to now go after some loot and he complies. Meanwhile, Thor recovers from the villain’s attack and he and Bennett pursue Damocles. When Ben learns that the superweapon is powered by synthetic cobalt, he informs Thor that the element is dangerously unstable and an explosion would destroy Manhattan. The Thunder God comes upon Damocles and the gang looting a diamond exchange and challenges him. As Thor is beset by the henchmen, Bennett warns Eric of the danger. Damocles does not listen but instead turns the cannon on Thor--and to prevent a disaster, Bennett scoops up a fallen gun shoots his brother down. Thor conjures up a vortex which carries the Cobalt Cannon into space where it explodes like a nova. Leaving Bennett to his grief, Thor admires the new star in the heavens….