Something of a surprise from the director of the Korean cult classic Oldboy, Park Chan-wook’s Thirst is, like all vampire movies, a really screwed-up love story, and like Park best-loved films, a sometimes hyper-violent meditation on guilt, suffering and vengeance. A saintly priest (The Host’s Song Kang-ho) offers himself as a test subject for a vaccine meant to cure a virus that causes a deadly leprosy. Things go badly, but the dying cleric is miraculously healed by a blood transfusion that profoundly alters his own biology. Much to his horror and shame, he finds he’s become a vampire.

The story ventures into a star-crossed saga of lust, infidelity and murder—by way of Zola’s Thérèse Raquin—when the priest is seduced by the sexually-frustrated wife of an old friend (Kim Ok-vin). Far from terrified, she’s becomes obsessed with her lover’s vampiric superpowers…and the nightmare begins!

I caught up with Park recently in New York, where he spoke through an interpreter. The professorial director was deliberate and thoughtful in answering questions, a far remove from the impulsive characters in his movies.

Vampires are big these days, in case you hadn’t noticed. True Blood. Twilight. And now your film. How did you manage to find a new twist on such an old story?

Park Chan-wook: I couldn’t have possibly intended to somehow revolutionize the genre. Rather, I was trying to come up with ways to take a Catholic priest and put him in the worst situation possible, where he comes to the lowest point in terms of his morals. In following that quest, I thought to have him as a vampire. I wasn’t trying to do something within those traditions of the genre. All I did was take away from things considered vampire conventions, such as the lengthening fangs or the fear of garlic or the crucifix, or things to do with mirrors, the fact that none of them cast shadows…none of it is in the film.

The movie really feels like a philosophical debate, or a man vs. woman debate. This priest does a sacrificial Christ-like thing but then becomes demon against his will. A girl who appears to be a victim somewhere longs to victimize. You seem to be examining man’s nature, and whether we should aspire to a higher calling or submit to primal desires.

Chan-wook: I have tried to deal with the existential situation human beings find themselves in, and also the horror that arises from that. We had this character who wanted to do a good deed, almost to the extent of sacrificing his own life, but despite his intentions becomes a demon. So, where does this come from? Where does this blood that turns him into a demon come from and whose blood is it? These are metaphors for the fundamental questions in our lives that are unsolvable. And the fear that you feel when you contemplate these questions. And I wanted to describe these. How you need to take responsibility for the sins you commit, even as you need to commit these sins in order to survive?

One thing I enjoyed about the film is that it’s such a rollercoaster of tones and moods. Some scenes almost feel like a musical. Others have the quality of silent-film comedy. And at its bloodiest, it’s also kind of a black comedy that

Chan-wook: If you have cast the right sort of actors, this is something that will take place naturally, as long as my actors understand what kind of filmmaker I am. Also, we have a lot of conversations, so they understand what my film is all about. The most important thing is for actors to have confidence in their performances. We try and avoid situations where actors are not confident.

Is it hard to shape the swings in tone?

Chan-wook: Throughout many years, the way I think is like that. It’s more comfortable for me to tell a story like that. Rather than, say, a shift in tones, I like to think that many different tones are thrown together in the mixture. When you look at my films, in a comedic moment you also have a sense of sadness. And when you feel something is scary, at the same time it could be funny. I think that’s the accurate way to perceive life. I make a conscious effort to think like that and express myself like that. It’s more comfortable for me to make films like that. If a producer came to me and said, “I want to you to do a film without one minute of humor in it, but to make it constantly like a horror film,” or if they said make a film that is only funny and doesn’t have a bit of sadness, it would be the most difficult film to make.

The sex scenes, while for the most part not terribly graphic, are really visceral and intense. How did you get the actors to pull those off?

Chan-wook: I don’t know about other countries, but in Korea people tend to be shy about sexual matters. These are the scenes I was most concerned with. I deal with this in the following way: First of all, when I’m writing the script, it can’t seem to be contrived. It needs to convince the actors that these scenes are an integral part of the story. I tend to draw a storyboard for every scene, but for this I put in more effort to include every detail for the scene, even down to the kind of lighting that would be used and positions the characters will be in and how much you actually see on the screen in terms of nudity as well. There won’t be any changes on set that would be unexpected. If the actors accept that, they will sign on. And if they sign on, I will try to be friends with them. Not only is it important for the actors to become friendly with each other, they need to become friendly with the director of photography and the camera operator and the director as well. When we’re on set, we have all the crew go outside the studio, except the minimum amount of crew necessary to do the shot. And we keep it to one or two takes.

So you’re not pulling a Stanley Kubrick on them?

Chan-wook: No [laughs].