The powerful but arrogant god Thor is cast out of Asgard to live amongst humans in Midgard (Earth), where he soon becomes one of their finest defenders.
Steve Rogers, a rejected military soldier, transforms into Captain America after taking a dose of a "Super-Soldier serum". But being Captain America comes at a price as he attempts to take down a warmonger and a terrorist organization.
With the world now aware of his identity as Iron Man, Tony Stark must contend with both his declining health and a vengeful mad man with ties to his father's legacy.