Ari Aster is ready to make audiences laugh. At least a little bit.

In Beau Is Afraid, the writer-director dips into what he calls a “nightmare comedy” for a change of pace from his previous films, Hereditary and Midsommar.

“The way I’ve been describing it from the beginning, and I think it’s the most apt way to categorize it, would be that it’s a nightmare comedy. It is in nightmare logic and I think [audiences] should walk into it with those expectations,” Aster tells That Shelf during a sit-down chat ahead of the film’s Toronto premiere. “I think it helps as well to just give yourself to it.”

Going in with the least amount of knowledge about Beau Is Afraid is the best way to experience it. Joaquin Phoenix stars as the titular Beau, an anxiety-plagued man who grapples with the sudden death of his mother Mona (Patti LuPone) with whom he has a close but complex relationship. Forced to confront his fears, Beau begins an odyssey to his mother’s home that would make Kafka proud.

For Aster, this story has been kicking around for some time. There was his 2011 short film Beau, which touched upon some similar themes that can be found in the expanded story that takes place in the feature.

“It always functioned as this receptacle for the ideas that made me laugh, these Rube Goldberg-like set pieces that the oldest draft of the script was–like a non-stop succession of absurd set pieces. I think most of the script resembled the first act of the film,” Aster says.

“The world of Beau was something that always stuck with me. That came to me very quickly.  I understood on an intuitive level; it’s very hard to talk about because it has been occupying my imagination for so long, but by the time I finished the first two films, I felt like I wanted to go there and live in that world for a while.”

With Phoenix on board, Aster says “very little changed from the page,” but for the most part, “it was really more about just investigating who this guy was because he doesn’t speak a lot and he’s pretty passive in what happens to him.  I think what Joaquin’s first feeling was that he took to the script and really liked something about it, but he was concerned that he wouldn’t have enough to do.”

Of course, Phoenix would soon be proved wrong as Beau has quite a lot to do in the film.

“He was telling me recently that he had no idea that he had so much to do. And to be honest, I like that,” Aster explains. “I knew that I needed somebody who is totally vulnerable and who had an emotional openness because I knew that Beau needed to be grounded in a way that the rest of the world wasn’t, that we would only have Beau to hold on to because the world itself is like a funhouse mirror of the real world.”

When it comes to working with Phoenix, Aster says the Oscar winner exceed expectations. “But even I was surprised by how much the role demanded of him walking, not just physically, but emotionally. It was amazing to see him give so much of himself,” he says. “I knew he would because I wanted to work with him for a long time because of the commitment that is always evident in his performances. Before I worked with Joaquin, my feeling was that he was one of the best actors in the world. And my feeling after having worked with him is that he was is that he’s better than I imagined he’d be.”

Aside from Phoenix and LuPone, Aster lined up a great supporting cast that includes Nathan Lane, Amy Ryan, Parker Posey, Julian Richings, Zoe Lister-Jones, Richard Kind, and a cameo from Bill Hader.

“It was such a joy to have that cast. And there are so many people in that cast that are just actors that I’ve loved since I was a kid,” he says. “It was a real trip to be able to work with [them].”

Another key cinematic figure Aster has been able to interact with while on the Beau Is Afraid press tour is none other than Martin Scorsese, who hosted a Q&A and screening at Lincoln Center in New York with Aster earlier this week.

“It’s hard to describe how meaningful it is to me because I think he’s the greatest living filmmaker and I think his body of work is basically the most intimidating and impressive [one] that I ever that I have known — and I’m talking about the entire history of the medium,” Aster shares. “But what he’s done in preservation, what he’s done for film history — he’s gone further than anybody else.”

Aster continues, “And then the way that he champions other filmmakers [has] always been very moving to me because he’s devoted so much of his time and life to that as well. And not only filmmakers of the past but new filmmakers and it’s really beautiful. I’m honoured and almost embarrassed, you know?  I’m very moved by it, and I love it.”

Beau Is Afraid opens in theatres on April 21. Read Victor Stiff’s review of the film here.