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.
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.
Earth's mightiest heroes must come together and learn to fight as a team if they are going to stop the mischievous Loki and his alien army from enslaving humanity.