As Topher Grace prepared for his first read for BlacKkKlansman last fall, he realized he was well outside of his comfort zone. “I had the weirdest audition ever,” Grace told THR of trying to channel Ku Klux Klan Grand Wizard David Duke. “I said to [director] Spike [Lee], ‘Look, it's your project but I just have to say how uncomfortable it is to say some of these words.”

But the That ’70s Show star said Lee instantly put him at ease, allowing him to “unleash like the worst things I've ever said in my life.” Not long before the film made its Cannes world premiere, Grace was finishing a looping session with Lee and asked for a peek at an early cut of the scene. “Every actor is always trying to see more of a film. So you say, ‘Ya know, for my motivation, I need to see the whole scene to understand the context.’ Spike goes, ‘Sit down, I'm playing you this whole reel.’ So we just watched the whole final reel of the film, which was devastating,” said Grace of BlacKkKlansman’s emotional finale, which splices in real footage of last year’s deadly Charlottesville protests in which Duke marched.

This year marked Grace’s first time at the festival, and his scheduled proved to be busy given that he also plays a supporting role in the festival’s Under the Silver Lake. Still, he sat down with THR at the InterContinental Carlton Hotel to discuss his mandate to work with auteurs (“I don’t need the money”), the prospect of a That ’70s Show reboot and his thoughts on former co-star Danny Masterson.

How did this David Duke role first got on your radar?

I read it, and thought it was amazing. There are some movies, when you say to your agent, “I want this.” They say, “We see it too.” This was one where everyone went like, “What?” But I had done a bunch of research after reading the script and I think I kinda look like this guy. What was really strange about rehearsing it before I went in to see Spike is you’re really trained in a good way not to say any of those words. So I was alone in my office in my house and having trouble saying the dialogue. And you do have to get comfortable saying it because the characters are obviously very comfortable. So it was just a weirder experience than a normal role.

Had the Charlottesville protests already happened when you signed on?

Yes, but I think this movie could come out any year. But there was something about it being in that kind of post-Trump America, the post-tiki torch America. I read [Ron Stallworth’s] book [on which BlacKkKlansman is based], and then I read My Awakening, which is kind of David Duke's Mein Kampf, which is disguised as his autobiography. It was very, very hard to read. And I watched a lot of him. The good thing about him being a public figure is he was on Donahue a lot. What I really gleaned most is how dangerous he is because he's so intelligent. And also he just kept using hot-button words like “America first” and “make America great again.” You can see it in his Donahue clips.

What made you take a supporting role in Under the Silver Lake?

I just thought It Follows was so unbelievable and [director] David [Robert Mitchell] is such a voice. I said I'll do anything on his new film. I just want to work with people like that. Five or six year ago, I thought, “Ya know, I don't have to do anything." I'm so happy [That '70s Show] was successful, and I really just want to work with auteurs, and that's what I've been doing. I don't really care what the size of the role is or what the perception of the role is or anything. I just really, really want to work with great directors. I just want to work with people that, like, on set are blowing your mind every day. My agents, by the way, do not love the fact that I only want to work with auteurs. I don't even mean to say it to brag. It's just you're in such a great position [after a series like That ’70s Show]. They don't really make TV shows like that anymore. I don't need the money. I remember sitting down with my team and saying these are the only kind of people I want to work with [like my Interstellar director Christopher Nolan]. I don't really care what it does to my career. I love it.

Who is the one director you're dying to work with?

Guillermo del Toro. Seth Rogen. I had this epiphany the other day. That guy is making all the great stuff and no one is giving him credit. What he's done over the last decade as a producer and what Evan [Goldberg] has done as a producer. I think those guys are doing some unbelievable work. John Krasinski. That's another director I'd love to work with.

He's got his Office money.

Trust me, there's more Office money.

Would you oppose or embrace a That ’70s Show reboot?

I would do it for sure because that was a very wonderful time for us. We were all very close, having that experience every single day with each other. It was great to broadcast it out once a week, but, like, I'm still great friends with those guys. So the fact that someone would pay us to go [hang] out together. If someone said to you, “What if I got your whole high school class back together and you hung out for a year?” Yeah, I don't think it will happen. It would be so hard to bring that crew together. For me, I'd do it if no one ever saw it. Just 'cause it would be great to hang out with them for a week or something.

You haven't spoken publicly one way or another about Danny Masterson. Do you support him?

You know, I hesitate to say that I never saw any of that behavior because I feel like it sounds like I'm defending him, but the truth is I never saw any of that stuff. I was, of that cast, the most boring. So when it came to going out after the show and partying, I just was boring.

A version of this story first appeared in the May 23 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.