Joining a team as closely knit and unforgettable as "The Avengers" has got to be something of a challenge, even for an actor like Aaron Taylor-Johnson, who has gamely appeared in "Kick-Ass" (and its follow-up) and last year's mega-successful "Godzilla" reboot. "Avengers: Age of Ultron," after all, is the sequel to the most successful superhero movie of all time, and one that stars a chummy group that includes Robert Downey, Jr., Mark Ruffalo, Chris Evans, Chris Hemsworth, Scarlett Johansson, and Jeremy Renner.

Add to that the additional pressure of playing Pietro Maximoff, aka Quicksilver, a super speedy Marvel character that audiences had just been introduced to the previous summer in Bryan Singer's "X-Men: Days of Future Past," and it sounds like a pretty daunting proposition. (He'll appear alongside his "Godzilla" co-star Elizabeth Olsen, who plays Quicksilver's twin sister, Scarlet Witch, as the two new kids on the block.) Not that Taylor-Johnson seems all that daunted.

We visited the set of "Avengers: Age of Ultron" in London last summer and got to chat with the actor about the ins and outs of Quicksilver, even if he was very reluctant to give us much in the way of details.

When his Eastern European accent came up, Taylor-Johnson said, "We're doing one. Whether they decide to re-ADR that in the end, I don't know." What's so funny about this comment is that, based on television spots that have been released for the sequel, it's apparent that they have decided to keep his accent and it's also endearing (and true for much of the cast) that they feel so lucky and overwhelmed to be a part of a Marvel project that are almost afraid that somewhere along the way someone is going to change their mind and pull them out of it.

In fact, Taylor-Johnson seemed nervous to give us all a taste of his accent. "I can't," he said flatly, before elaborating. "Me and Lizzie have been doing dialect coaching together and trying to get that sound similar to playing twins. But it's fun, when I spoke to Joss about it a long time ago and he approached me for the role, it was one of the things I wanted to keep."

And Taylor-Johnson's accent isn't the only thing he wanted to preserve from the original character. "I wanted to have white, silver kind of hair to look like the character and I could kind of embrace the roots, where he's from, being Eastern European. It would be great to do some kind of accent to impart that kind of feeling so -- so I'm glad that we're doing it. Again, his nervousness kicks in: "But like I said, you know, they might screen it and go what are they saying? I'd like to think that they'll keep it there and you know, the Marvel guys, they totally understand; they're a studio that really cares about their characters and have real creative input." Then, optimistically: "Hopefully it will continue on that route.

Unlike some of the other actors, Taylor-Johnson has also read up on the character's comic-book roots. When asked if he's been reading the comics, Taylor-Johnson said, "Yeah, sort of a mixture of things. Obviously the character jumps in and out of different universes being in their mutant world and all that, which obviously we don't embrace cause of being with Fox and that extent as you're all aware. That's no secret, you know. So I take bits that have been done in history and all sorts of comic nooks to get an essence and the sense of Pietro as a character rather than Quicksilver just in the sense of Oh yeah, superheropowers that he runs faster than the speed of sound. I wanted to know what's he really like and get to the depths of him."

The relationship between Quicksilver and Scarlet Witch is also a huge part of "Avengers: Age of Ultron," which Taylor-Johnson elaborated on. "He's very protective of her in a physical way and her more in a psychological way so we try and embrace that and there's a lot of stuff that we could pick up from."

Not only was the relationship something new, but Quicksilver's powers are also something that is new to the franchise. As Taylor-Johnson said, "I run a lot." Not that Taylor-Johnson was all that sure about how that running would be brought to the screen. "Right now, I think they're gonna play around with maybe getting into Quicksilver time, which would be my point of view and playing around with that. That's another thing that's experimental really. With new powers and things like that, you can really play with that sort of stuff. The first time we did a running test, I was on what's essentially a running machine but it was a huge lorry-sized rig that was something that they sped up and it was a great big running machine, and they had me on a harness on a green screen." (Taylor-Johnson also said that they filmed some scenes in 120 frames-per-second, which gives that dreamy slow-motion quality.)

Of course, an inherent part of these movies is obviously the humor, largely supplied by the quip-happy writer/director Joss Whedon. "Yeah, with the Marvel Universe in general is everything's not taken seriously in a sense of even when there's points of real drama, but I love that there's a lot of sarcasm and humor to it, and people have their moment of humor and I guess, you know, it's fun. What we didn't want from me and Lizzie's standpoint is that our accents to be the humorous thing. Like I said, it's all fed through Joss and bouncing off some of the other actors and stuff." When someone asked if his repartee is mostly with Scarlet Witch or the rest of the team, Taylor-Johnson shot back: "With the rest of the team." Taylor-Johnson just elaborated: "You know, it's always that great thing where they have characters going head to head and bicker with one another and I don't want to say who...."

The inevitable comparison came up between Quicksilver in "Avengers: Age of Ultron" and Quicksilver in "X-Men: Days of Future Past" (which, at the time of our set visit, had just come out). When asked if they would shift their dramatization of the character in the wake of "X-Men: Days of Future Past," Taylor-Johnson didn't think so. "I haven't seen it yet so I don't really know. I don't feel. When the job came around, it was already out there. I think it was already shooting, you know, so it wasn't like we were like all, Oh, should I really be taking on a character that's already...? I don't feel threatened nor do we go like we're saying that's the wrong thing. It's just that's one thing and we're doing something different."

The inevitable question of a spin-off or solo movie came up. "I wasn't thinking on that line. They'd probably sort of tag us into someone else's, you know. They've got their own comic book, so there's got to be something. It's up to the Marvel guys, if they kind of wanted to go that route." But as to whether or not he'd be game to return, he didn't have to even think. "Absolutely, with these guys, it's a lot of fun. It's a great studio to be a part of and I'm not just saying that, 'cause it's like that. That's the kind of easiest thing to say. It's like, you know, you work with other big sort of studio movies and you're just one of the films in the mix of many others and you're just a character and many other in their films. Marvel guys only care about the Marvel Universe and the characters they came from so therefore that's all they think about creatively and care about. And they care about the storyline. So it becomes a really creative kind of family and a place that, yeah, I enjoy working. So the experience for me is always overall whatever the outcome is or whatever so cause this is how I work, and it's part of my life and important to have fun and work with good people, you know."

"Avengers: Age of Ultron" opens everywhere May 1.