David Sims: I know Parasite initially started out as a play. What was the genesis of that idea?

Bong Joon Ho: I have a close friend who’s a stage actor, and he suggested that I try directing a play. Of course, with theater, the space is limited, but for all my previous films we had a lot of locations—like, Okja starts in the deep mountainside [of Korea] and ends in Manhattan. So I was thinking, What story could I tell with just two houses? I came up with the idea of a poor house and a rich house, because at the time I was working on the post-production of Snowpiercer, so I was really enveloped in this story about the gap between the rich and the poor.

Aside from Snowpiercer and theater, I was fascinated with this idea of infiltration. When I was in college, I tutored for a rich family, and I got this feeling that I was infiltrating the private lives of complete strangers. Every week I would go into their house, and I thought how fun it would be if I could get all my friends to infiltrate the house one by one.

Sims: You’ve worked in the world of allegorical sci-fi and fantasy in recent years. Did you consciously want to move away from harder genre films while keeping up the allegory?

Bong: Sci-fi gives you the advantage of being able to say what you want pretty directly. Like, in Snowpiercer, that scene where Ed Harris has a long monologue in the engine car. Parasite has the landscape stone [a gift given early in the film that becomes crucial to the plot]. The movie has symbols, but I wanted to focus more on the mundane atmosphere, on the stories of our neighbors.

Sims: But Parasite still has the quality of a haunted-house story.

Bong: Yes, it’s still a genre movie, and there is some kind of ghost story. In this story, the characters treat a normal person like a ghost, so you can say that’s social commentary [and] a genre element. I think in my films, it’s always difficult to separate the two.

Sims: So many of your films are about people contending with monsters they don’t understand. That’s going on in Parasite as well; there’s a gulf these two families can’t breach.

Bong: I haven’t heard this comment in a while! If you think about it, my films are always based on misunderstanding—the audience is the one who knows more, and the characters have a difficult time communicating with each other. I think sadness and comedy all come from that misunderstanding, so as an audience member, you feel bad—you want to step up and reconcile them. As a filmmaker, I always try to shoot with sympathy. We don’t have any villains in Parasite, but in the end, with all these misunderstandings, they end up hurting each other.

Sims: The design of the two houses is everything for the story—it sets up how these families exist so differently. How did you approach that?