Before you continue reading, I should warn you that the new details that have been revealed thanks to Digital Spy are pretty spoilerish. If you don't want to know what happens in the movie, I would suggest you stop reading this post now.
Digital Spy was able to visit the set of AVENGERS: AGE OF ULTRON last summer. While on the set, they learned a bit of what to expect from the movie, and they also had a chance to talk to a few of the stars from the film. Below I have listed a few of the most interesting bits from the article:
The Science Bros are causing trouble. "Banner's been living in Stark Tower, and [he and Tony] have been working side by side," Mark Ruffalo shares. "Banner has his own lab now, he's doing work that augments Tony's work, that could lead to a horrible experiment going wrong…"
when the Hulk almost ripped her apart. "They're an unlikely pair, but there's something about the two of them that neither can deny," says Whedon, while Ruffalo describes them as "kindred spirits".
"The story that Joss put together with these two kids is really sweet and poignant, and you really understand why they would start on this side of the line. It's a great journey that they go on, from being these rough and tumble kids in Eastern Europe who blame the West, and the Avengers for the plight, the power structure of the world that keeps kids like them down. Over the course of it they realize maybe the Avengers are here for good reason."
But the brother-sister duo have legitimate beef with one Avenger in particular. "Our characters have a lot of anger, especially towards Tony Stark, and we want revenge," says Olsen. "We meet Ultron, and he's someone who preaches peace and… believes what we believe, which is that the Avengers create destruction and that Tony Stark's bomb is responsible for killing our parents."
Unsurprisingly, their alliance with Ultron ends up turning sour, and Olsen reveals that "my character ends up really having to deal with her ignorance. A lot of problems that happen towards the end of the film are her responsibility."
– but it's a tightrope walk for Whedon. "We have to honor all of that, and also ignore it, because not only can Steve not be busy looking for Bucky in this film, but he shouldn't make any kind of progress on that at all.
"Some people don't see this, they only want to see the Captain America movies. In comic books, if you do a big crossover event, back in the old days the solo books would just carry on. Now it's sort of like if you buy one, you have to buy them all, and I never want to do that. I don't want to make a movie where you have to have seen the other movies. So it comes up, because we have to respect what they've all been through, but this film is a simultaneous side-bar."
Source: Digital Spy.