Being the cornerstone of a whole film universe is daunting. Or, at least it would be daunting for anyone other than Joss Whedon, who made the culmination of Marvel Phase One, The Avengers, into one of the highest-grossing films of all time. Soon after its success, it was announced that Whedon would return to do the same symposium of superheroes for Phase Two, and that it would be subtitled Age of Ultron, due out May 1st. Based entirely on the look of the trailers, it’s going to be pretty amazing. At a set visit to Shepperton Studios last year, the same one that produced the Robert Downey Jr. and Mark Ruffalo interview last month, we and several other outlets got to speak to Mr. Whedon about how he’s doing Avengers differently the second time around.

The first Avengers was not a particularly refreshing experience for Whedon. “The first one, I was raggedy. I was a raggedy, raggedy man when I made that film,” he said, saying that he had to shift the way he was working for Age of Ultron. “Going in this time, I just had to sort of recalibrate my entire existence and throw myself into it more wholeheartedly and say, okay, actually make it harder to make then the last one, and I’m gonna just invest myself in every part of it- in every production meeting, every location scout, and every question about a prop that I’d like to avoid, and every- I might even work harder on the script.”

And everything has also grown along with the difficulty of the work being done. “The cast is bigger. The scope is bigger. We have more to work with. Not that we’re trying to spend more, in fact, we’re trying to avoid bloat wherever possible. But, you know, with this, we’re on a broader canvas. We’re in more countries. We have a bigger world to work with, and a bigger world for them just to be in.” He adds that the Avengers now have a lot more eyes watching them than when they protected New York. “Once they exist as a team, we have to deal with what everybody thinks about that, and what that means to the world. It’s not as simple as it was.”

Obviously, most of the eyes of the audience will be looking at the new heroes, who probably won’t start out as heroes: Quicksilver (Aaron Taylor-Johnson), Scarlet Witch (Elizabeth Olsen), and the Vision (Paul Bettany), the latter of whom was part and parcel to Whedon’s desire to make the film. “I wanted Paul to play this part since before I wanted to make Avengers movies,” he said, adding that the actor’s face is something to behold. “It’s about cheekbones, people!” But the character is also someone Joss had in mind since before the success of the MCU was even secured. “Before I took the first job, I said, “Well, I don’t know if I’m right for this or if I want it or you want me, but in the second one, the villain has Ultron, and he has to create the Vision.”

Whedon also wanted to bring in the siblings, Pietro and Wanda, to bring a new dynamic in the film. “They’re from my era,” he said. “They’re very different, their powers are different. It’s not all punching, it gives a different palettes. We can do more interesting things, it’s fun; those things were all, yeah, those were absolutes. But then I didn’t actually want to make the film necessarily.” Whedon took some convincing. “I was ragged from the first one, and so I just turned off my brain. I was like, ‘Do not think of cool ideas for the next one. Just get through this.'”

The writer-director told us the only reason he took the job was because his fount of ideas started flowing and couldn’t stop. “My agent called, I was in London, and he called and said there’s a deal that’s worth talking about; time to start to think if there’s a movie. And I’m going, ‘all right.’ I went to a pub, and sat down with my notebook, and about forty-five minutes later, my notebook was filled. And I texted my agent ‘yup, and I have so many things to say’ and I was kind of surprised. It took me unawares. It was very beautiful.”

One thing many fans have been excited about is seeing more of the Hulk, the real breakout star of the first film. Whedon understands this, and that fans want to hear more Hulk-talk, but is also wary of overdoing it. “I pitch it and I take it away. It’s moment to moment. Done wrong, it could kill ya.” There’s a balance that has to be struck for Hulk to work properly, Whedon says. “Just what makes the Hulk so hard to write is that you’re pretending he’s a werewolf when he’s a superhero. You want it vice-versa. You want to see him, Banner doesn’t want to see him, but you don’t want Banner to be that guy who gets in the way of you seeing him. So the question is, how has he progressed? How can we bring changes on what the Hulk does?”

Ultron is obvious the big linchpin of the movie, it being the age of him and all, and Whedon made sure that the giant robot played by James Spader was a character with genuine motivation beyond simply being a baddie, something both he and Spader wanted to avoid. “Ultron feels a certain distance from humanity,” the director said. “The day Spader got here we put on the mocap pajamas, a giant thing with red dots on it for his eye line, and, you know, giant pack, and a helmet with two cameras in his face with lights to record his performance. He then did a scene with Scarlett [Johansson], but she couldn’t look him in the eye, she was looking up in his eye line, and nor could he see her because he had two lights shining in his face, and he had his glasses on. Therefore [Spader] has a certain distance from humanity, too.” Spader and Whedon saw eye to eye on the character, the director divulged. “He and I share a genuine love of this version of Ultron, and he has an innate eccentricity in his delivery that is everything that I had hoped Ultron would be.”

The writing of Ultron proved especially challenging, given that he has a specific ethos he’s trying to implement. “There’s always a point where I’m writing where [I think about the villain] ‘they’re right! The Avengers sucked! Got to do something about that. We got to take care of these guys,'” he said. “Hopefully, you will come out of this, if not agreeing with him, getting him, and getting his pain which leads to a lot of damage, and some humor.”

If one thing can be said of Whedon, it’s that he’s not looking too far ahead, to anything in The Avengers franchise beyond this script and this shoot, and dreaming up ideas for future installments is fruitless. “There comes a point in filming when you are writing, filming and editing, and you cannot make a grocery list,” he said. “I haven’t had a good idea about anything. I’m so excited that I’m wearing underwear, that I got that right today. We’re just past the halfway point, and I’m still finessing and finessing and finessing, and I got nothing. So it’s, you know, I do this, I go home, I rewrite, I go to sleep. I do this, I go home, I rewrite, I go to sleep.”

The Avengers: Age of Ultron is anything like the first Avengers, I think we can be pretty confident that Whedon’s workmanlike approach to making massive superhero movies is the right on. Age of Ultron will premiere, and surely decimate the box office, beginning May 1st, 2015.