Avengers director Joss Whedon has made a surprise appearance at the Marvel Studios presentation at Comic-Con.
He offered an early look at the sequel. A teaser trailer for Avengers: Age of Ultron ended with an image of the title character.
Thor's evil brother, Loki, took over the presentation at one point - lights flashed inside the San Diego Convention Centre's largest exhibition hall as actor Tom Hiddleston commanded the stage.
He called Hall H "a meager palace of Midgard" before showing footage from Thor: The Dark World. It opened with an epic battle scene, in which Thor takes down a massive monster, reducing him to a pile of rubble with one swing of his hammer.
The cast of Captain America: The Winter Soldier shared footage from that film. It also opened with a dynamic fight scene: Captain America battling a dozen assailants in a glass elevator.
Other highlights included the introduction of the Guardians Of The Galaxy cast, which includes Chris Pratt, Zoe Saldana and Djimon Honsou.
Mixed martial-artist Dave Bautista said he fought hard for the role of Drax. "It's something I wanted more than anything I've ever wanted in my life. When I got the job, I broke down and cried like a little baby," the tattooed bodybuilder said.
Kevin Feige, head of Marvel Studios, said Guardians is the company's attempt to push the Marvel cinematic universe in new directions beyond The Avengers franchise that might not be familiar to the casual fan.
The film takes place on the other side of the universe for the most part, he said, and features non-humanoid characters that will require computer-generated images to pull off.
"It's a very important movie for us for expanding the definition of what a Marvel Studios movie can be the way Iron Man one was a very important movie for us," Mr Feige said in an interview. People didn't know if Marvel could do it by themselves. They didn't know if Iron Man was an A-list character."