Spoiler warning: There will be spoilers for Ant-Man below.

When The Hollywood Reporter announced that actor Martin Donovan had joined the cast of Ant-Man back in October of last year, they were unable to reveal his role – only going on to state that it was a pivotal one. It actually wasn’t until the Ant-Man premiere in Hollywood earlier this month that we learned that he’d be playing. Donovan had joined the film as Mitchell Carson, a S.H.I.E.L.D. operative from the Marvel comics that goes on to become a rival of Eric O’Grady, the third Marvel character to go on to use the Ant-Man moniker.

In the film, we first meet Donovan’s Mitchell Carson in the opening flashback scene, alongside Howard Stark (John Slattery) and Peggy Carter (Hayley Atwell), as they are confronted by a frustrated Hank Pym (Michael Douglas). We then see his character later on, present day, when Darren Cross (Corey Stoll). unveils the Yellowjacket suit. At this point, Carson is no longer involved with S.H.I.E.L.D. and is there on behalf of Hydra to make a bid on the Yellowjacket technology.

Donovan’s Carson made it out of the first film alive, with the particles in hand, leaving an open door for the character to return down the line. While speaking to Comic Book Resources, Donovan talked about his character’s future in the Marvel Cinematic Universe, how they de-aged him for the opening scene, and what it was like to be a part of a project like Ant-Man.

CBR News: Carson’s an intriguing character. Did Marvel give you a sense that he’s more important to the overall universe?

Martin Donovan: I’m supposed to be vague! I’ve been told to be vague! But vaguely: he’s in the Marvel Universe, and we’ll see.

We see him in two different time periods. Tell me about working with the de-aging techniques they used for the ’80s sequences.

Donovan: Well, it was makeup and I haven’t seen the final result, but I’m told that it looks pretty amazing, and I’m sure they did all this other stuff to make it even more amazing. But even the makeup was really well done, so whatever they did on top of that [with technology] I’m sure it’s going to look amazing. I had a couple of hours in the chair every morning, every day, but it was all good. It was fun. Fun to do both.

What was cool about seeing the scale of this project?

Donovan: I mean, some of the sets was just — a single set cost more than the entire budget of a lot of the films I’ve done. [Laughs] So it’s just extraordinary. And then you see when they have the budget, how creative and how incredibly talented people are. I mean, there’s so much talent out there. These designers, these technicians, the art department, the sets, the wardrobe, everything about it, you realize there’s just — I mean, it’s just exciting to be around such creative people, such talented people. It’s great.

Ant-Man is currently in movie theaters. The film has so far grossed over $220 million worldwide. As it stands, a sequel has not yet been announced.

Source: Comic Book Resources.