Heroes 'Geek Out' on 'Avengers' Set

Marvel's explosive, action-packed movie The Avengers imagines what it would be like if some of the greatest superheroes – and egos – ever assembled to battle a common enemy. While the likes of Iron Man, Captain America, Thor and The Hulk initially clash onscreen, it was just the opposite on the set of the highly anticipated summer blockbuster.

"We geek out a little bit," admits Robert Downey Jr., who once again portrays Tony Stark, aka Iron Man.

"We do that a lot," concurs Mark Ruffalo, who is taking on the role of Bruce Banner, aka The Hulk.

Watch the Epic 'Avengers' Trailer

Only ET's Mark Steines was on the top-secret, six-soundstage Avengers set in Albuquerque, NM to hang with Downey Jr., Ruffalo, Scarlett Johansson (Black Widow), Chris Evans (Captain America) and Chris Hemsworth (Thor) for what could well be the greatest superhero movie ever made.

Did Downey Jr. convince Ruffalo to come aboard the movie? Was Johansson able to go toe-to-toe with the fellas? Did the stars collectively feel like it was one big Halloween party in those insane costumes? Watch the video to find out.

'The Avengers' Assemble in Killer Poster

In theaters and IMAX on May 4, Marvel's The Avengers follows the daring recruitment of the crack team of superheroes by Nick Fury (Samuel L. Jackson) of S.H.I.E.L.D. in order to pull the world back from the brink of disaster from an unexpected enemy.