Joss Whedon's inspiration behind 'The Avengers: Age of Ultron' comes from 'The Godfather Part II'.
The 49-year-old director admitted the 1974 American crime film, directed by Francis Ford Coppola, which is both a sequel and prequel to the 1972 original, was a "guiding star" for the forthcoming sequel to 2012's hit 'The Avengers'.
'The Godfather Part II' received great critical acclaim when it was released and was nominated for eleven Academy Awards in 1975, including the first sequel to win for Best Picture.
Whedon told French website AlloCiné: "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 [from Part I], 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."
Whedon will be careful about how he structures the highly anticipated film and although there might be nods to other superhero adventures he is planning on creating something which audiences can understand without having watched the original.
He added: "I can't assume that everybody went to see 'Thor: The Dark World', 'Captain America' and 'Iron Man 3' in between. I have to go from one movie to the next and be true to what's happened [in the previous movies], but not be slavish to it.
"The events of 'Captain America: The Winter Soldier' will definitely affect the world of 'Avengers 2'.
"But at the end of the day, I have to make my movie assuming that people will only have seen the first one, or possibly not even seen the first one."
In related news, it's believed Marvel are planning a third 'Captain America' movie.
The studio are said to be impressed with production on sequel 'Captain America: The Winter Soldier' - which is due for release in April - and the response to recent test screenings, so have moved to secure directors Anthony and Joe Russo for another installment in the franchise, which stars Chris Evans in the title role.
According to Variety, though the project hasn't yet officially been greenlit, it is likely negotiations on a third movie will begin once the second film hits cinemas.
Kevin Feige will produce the project, which doesn't yet have a writer or tentative release date.
However, Marvel and the directors are said to be already putting together an outline for the story.
Evans has a multi-movie contract with the studio so would be likely to return for another installment in the series, as would several other cast members.
The Russo brothers took over directing 'Captain America: Winter Soldier' in 2012, taking over from Joe Johnson, who helmed the first movie, 'Captain America: The First Avenger', which was released in 2011.
'The Avengers' grossed $1.5bn dollars worldwide putting it third in the all-time movie grossing list, with only 'Avatar' and 'Titanic' above it.