mark ruffalo avengers age of ultronWhen Mark Ruffalo was cast as Bruce Banner, the mild-mannered scientist who, when seized with a fit of rage, morphs into a towering green giant colloquially known as The Hulk, movie fans rejoiced. Even though Edward Norton had just essayed the character in an above-average movie for Universal, Ruffalo was a more exciting prospect. As an actor, Ruffalo is affable, approachable; this was a Hulk you wanted to cuddle up with (before he broke every bone in your body). Still, it was something of a surprise just how much of scene-stealer Ruffalo's Hulk turned out to be. Ask anyone who saw 2011's "The Avengers" (and, judging by its $1 billion+ box office haul, that translates to "ask anyone") and they'll tell you that their favorite part of the superhero smorgasbord was the Hulk.

Back in June, when we visited the set of next year's feverishly anticipated sequel "The Avengers: Age of Ultron," Ruffalo didn't seem phased by his popularity, or returning for what will undoubtedly become one of the biggest films of the year (or, you know, ever). Dressed in a dull grey bodysuit (most likely for performance-capture purposes), Ruffalo seemed like he was just happy to be invited back to the party. Like maybe his invitation could've gotten lost in the mail.

"I was just happy that I was in the movie at all," Ruffalo said earnestly, after joking that his grey jumpsuit didn't have any pockets (a reference to the first film's set visit, when he unlawfully showed off early Hulk designs to a group of eager journalists).

And where is he at the beginning of "Avengers: Age of Ultron"? As it turns out, he's engaged in a very different, possibly romantic relationship with Scarlett Johansson's Natasha Romanoff, aka Black Widow. And we're not being coy here; we really don't know and the powers-that-be were keeping a close eye on what the actors could and couldn't say.

"There's a really important relationship between..." Ruffalo said, before trailing off. Finally he continued, in his signature Mark Ruffalo way: "Any scenes that I got to be in with her were a big bonus."

One of the more memorable Banner lines from the original film is when he confesses that his secret is that he's always angry. Of course, things are very different this time around. "We left the last time with this idea that you know I'm always angry and therefore I have some control over it," Ruffalo explained. "But anger, when you think you have control over it, you absolutely don't." He went on: "There's a wrangling going on... a confrontation brewing between the Hulk consciousness and the Banner consciousness and I think we're starting to head into that right now."

Tony Stark (Robert Downey Jr.) and Banner obviously formed a tight-knit unit in the first "Avengers," and that relationship was teased further in the tag for "Iron Man 3." Together, the scientists are responsible for giving birth to Ultron, the titular villain voiced by James Spader, a grandiose robot with plans for world domination (Ultron is designed by Banner and Stark as a way of protecting Earth, before his artificial intelligence decides that the best way to protect Earth is to rid it of humanity). Ruffalo confirmed that, yes, their bond continues. "Tony took the orphan Banner into the fold. I was just made aware that my apartment was in Stark Tower." (Note: It is -- we got to see it!) "Tony's working on his own stuff, and you know they complement each other. They've got a short hand together. And yet they don't really know how to work well together. It's cool, it's cool."

There was production art released that showed Tony wearing an Iron Man suit described as a "Hulk buster." When asked to clarify this, Ruffalo said that it's a game of one-upmanship between Tony and Bruce. "It's a little bit like 'Cool Hand Luke' that way," Ruffalo said coyly. "There's a little twist to it as well." He then turned to the unit publicist, who bears a striking resemblance to Ruffalo, and asked, "Is that alright Barry?" (It was.)

When asked about how the Hulk fits into the team this time around, Ruffalo responded that he's trying... as much as the Hulk can try. "I think he's trying to become more a part of a group. I don't think he's ever felt like part of a family or part of something. He's always been outside or on the run or trying to shun humanity." It seems, in fact, that he has softened a bit. "But now I feel like he has the idea that maybe he is part of something and feels more comfortable, I think, you know, with the fantasy that he could actually be a part of something."

Not that the jolly green giant is completely at ease: "I still think it's a struggle for him, and I never think that he quite has it under control." Could happiness ever befall the Hulk? Maybe. "I think in this version he's as close to having a normal life as he possibly could." This normal life could include that alluded-to Black Widow relationship. "It might include...some romance. Is that ever possible for Banner? That is really the question." Yes, yes it is.

Still, he admitted, it's tricky to allow for actual character development when, according to Ruffalo's math, "It's ten minutes of screen time for each of us if we include the bad guys. And so it's hard to really do a lot of character development in it." Not that it's totally thin when it comes to the characters. "I think this movie goes even more into that than the last one, for everybody. And you're sort of playing catch up. But also I think you want to be ambiguous enough not, not to cover too much ground so that you have somewhere to go if they ever do want a stand-alone." He paused. Then added: "Another stand alone."

Ruffalo described the advancements in technology (aided by Andy Serkis's assistance) but said that, at its core, it's fairly rudimentary, at least from his end. "It's very much like theater because it's all imagination. You know you don't have a forest in front of you in the theater. You have to put that there for yourself. And so the theater training I had is very, very much in tune with this oddly enough." He summed it up as: "The oldest form of acting all of a sudden meets the newest form of acting. And they're very compatible to each other."

Of the new characters, Ruffalo said he most loves Elizabeth Olsen's Scarlet Witch, who has powers to unlock people, psychically, unleashes "a bad trip" when she messes with the Hulk. "I love the new kids on the block," Ruffalo said. "They're cool. They're really cool." Of course, one of those characters, The Vision (played by Paul Bettany), is a character he describes as "My baby." Ruffalo went on: "He is so dope. People are going to love The Vision." As for Ultron, Ruffalo confessed that the two have "a lot of scenes together." Then, "It's like King Lear." Um, sold!

Returning writer/director Joss Whedon, who spoke with us earlier, said one of the themes of the movie was the idea of being destroyed by power. This theme very much played into the Hulk's character arc. "That's the essential struggle that he's had throughout his life. But specifically in this is that you know he does have that destructive side of him. It's that it's not going to ever go away and you could have a little fantasy that it might be under control. And there's that conflict that is always going to be there that he might never resolve that. That's because that power is really destructive."

Even after all this time, he seems to be searching for a solution. "He, wishes he could find it. It's like you get to be a certain age and you have to start to practice radical acceptance or you just keep banging your head up against the same wall. And I think he's starting to get to that place where he's like, "Okay, how do I live with this? How do I make it work for me?' It's like management. It's like having a slipped disc." And with that, Ruffalo boiled down one of the greatest monsters in the history of comic books into the suburban golfer who spends too much time on the range. And it was perfect.

Finally, at the end of the interview, with Ruffalo slumped down in his seat, outfitted in that ridiculous grey jumpsuit, someone posed the question as to whether or not the Hulk and Bruce Banner could coexist. "I don't know," he sighed. "There's serious tension there and it's only growing."

"Avengers: Age of Ultron" hits theaters May 1, 2015.

Check out New From Moviefone on LockerDome on LockerDome
Avengers: Age of Ultron
Based on 49 critics

Things go awry when Tony Stark tries to jumpstart a dormant peacekeeping program. Read More

categories Interviews, Movies