Avengers Assemble reunites the team, along with newcomer Falcon, marking the first time in animation history this distinct team of heroes will join forces. Led by Iron Man, the heroes train and live together in their new headquarters in Avengers Tower. The planet's most dangerous villains don't stand a chance against Avengers Assemble. Whether they are stopping Doctor Doom from conquering Asgard, Attuma driving the Atlantean Army into New York City or Dracula unleashing vampire hordes, the Avengers must work together to succeed.
An even more powerful Ultron resurfaces and takes control of Avengers Tower and Iron Man's Hall of Armors, leading to the destruction of the Avengers as we know them.
Iron Man and Captain America try to rebuild their relationship, until Cap discovers Iron Man's hiding dangerous information about an artificial intelligence unit named Ultron.