Relates the earliest adventures of the Incredible Hulk, based on the original comics, describing the life of Bruce Banner, from his shy childhood to his military career and the experiment that went wrong.

Tells the story of a boy named Charles Xavier who discovers that he is a mutant with special powers, how he decides to use those powers to protect humanity, and how he starts a school to teach mutants to use their super powers for good.

Relates the earliest adventures of Captain America, based on the original comics, describing the life of Steve Rogers, from attempting to join the Army at the start of World War II, failing the physical examination, to being recommended for the classified Project: Rebirth, being injected with the Super-Soldier serum, and becoming America's first Avenger, Captain America.

Tells the story of Thor, prince and great protector of the realm Asgard, whose father Odin strips him of his memory and power and banishes him to Earth to learn humility, the only virtue he lacks, so that he might wield the mighty hammer Mjolnir.