When it comes to making sequels Joss Whedon has gone back to the classics for Avengers 2. Whedon watched The Godfather Part II to help inspire the movie and help with the transition.

In an interview with Allocine, Whedon said,'The model I'm always trying to build from, or my guiding star, is The Godfather: Part II, where a ton has happened in between and it's a very different movie, but you don't need any information.It's there in the film about what's happened since, what's different, and why is this a different film; why is it a different kind of structure and why is it darker?'

It's all there, you're in the vernacular of the first movie and you're just ready to pick up in this new place, and hopefully that's what will happen with my movie,' he added.

The sequel is said to be a little bit darker than the original. Mark Ruffalo recently said, 'I would say that it's better, it's cooler, it's more awesomer, It's a little bit darker, but also really has Joss Whedon's incredibly witty and sly sense of humour.'

The highly anticipated second movie will see all the original cast return, while they will also be joined by James Spader, Elizabeth Olsen and Aaron Taylor-Johnson.