Director Joss Whedon talks with Scarlett Johansson (Natasha Romanoff/Black Widow) on set

Chris Evans returns as Steve Rogers/Captain America

Tom Hiddleston stars as Loki, the movie's primary antagonist

Chris Evans and Robert Downey Jr. star in The Avengers as Steve Rogers/Captain America and Tony Stark/Iron Man

Samuel L. Jackson reprises his role as Nick Fury

Scarlet Johansson (Natasha Romanoff/Black Widow) and Jeremy Renner (Clint Barton/Hawkeye) get into the action on the set of The Avengers

Robert Downey Jr. (Tony Stark/Iron Man), director Joss Whedon, Chris Hemsworth (Thor) and Chris Evans (Steve Rogers/Captain America) on set of The Avengers

Jeremy Renner (Clint Barton/Hawkeye), Chris Evans (Steve Rogers/Captain America) and Scarlett Johansson (Natasha Romanoff/Black Widow)

Scarlet Johansson stars as Natasha Romanoff/Black Widow

Chris Hemsworth (Thor) and Chris Evans (Steve Rogers/Captain America) take stock of the challenge facing the Avengers team

Director Joss Whedon talks with Mark Ruffalo (Bruce Banner/Hulk) and Robert Downey Jr. (Tony Stark/Iron Man) on set of The Avengers