The Marvel comic heroes must align and learn to fight as a team if they are going to stop the mischievous Loki and his alien army from oppressing humanity.
By crafting a winning combination of wonderful characters, brilliant comedy, and spectacular set pieces, Whedon hasn't simply created the biggest superhero movie; he's created one of the best.
If you are a Marvel fan, then The Avengers will feel like Christmas. Thanks to the merry doings of the director, Joss Whedon, all your favorite characters are here, as shiny and as tempting as presents under the tree.
Whedon, a pop-genre magician best known for Buffy the Vampire Slayer, is a master of viewer manipulation - because he never gives up his own seat in the crowd.
Robert Downey Jr's billionaire playboy inventor Tony Stark, aka Iron Man, gets the film's self-aware, tongue-in-cheek tone spot on, delivering Whedon's wisecracks with sardonic charm.
Ultimately, it all comes back to Whedon: His clear vision for each character and how they might be profitably intermingled; his unexpected knack for action choreography; his funny, tender, immaculately constructed script.