Chilean director  Nicolás Postiglione teamed up with filmmakers Moises Sepúlveda (“The Illiterate”) and Agustín Toscano (“The Snatch Thief”) on his debut feature film, “Immersion,” a suspenseful descent into paranoia, instinct, and hubris. The film follows a family’s day sailing on the lake and how their vacation unravels wildly as they stop to help some local fishermen whose boat is taking on water.

Chilean star Alfred Castro, a Pablo Larraín regular, heads up the cast as the family patriarch, bringing weight to a solemn character around whom the tragedy unfolds. Postiglione explores themes of family, class, and fear in this parable which holds a mirror to the prejudice inherent in the gut. “Immersion” was picked up by Latido Films at 2020’s San Sebastian for world sales rights.

Variety spoke with Postiglione ahead of the film world premiering at Guadalajara.

“Immersion” feels in some ways Shakespearean in its familial tension and looming tragedy. What influenced you to tell this story, and in this way?

The tension that develops within the family was included to aggravate everything that happens during the film. The differences between father and daughter, the way they simply can’t agree, is what pushes them towards tragedy. I believe that these small differences in behaviors, familial tensions, can build up and develop into something much larger if the setting is right. Stressful situations spark all our wickedness, the tragedy was just the final punch that taught our characters a deadly lesson.

What challenges did you face, both in logistics and cinematography, filming the majority of the picture on the water?

Filming this movie was without a doubt the hardest shoot I’ve ever been on. Limited funds meant we didn’t have a large array of boats, or specialists that could ease the shooting. And water felt like lava – you can’t touch it, you can’t cross it – and just walk over to an actor to give directions. Added to that, everything is constantly floating and moving, which means you have to be quick with the camera and hold the frame right. Changing a lens or adding a filter meant rebooting the entire setup.

“Immersion” was co-written with fellow filmmakers Agustín Toscano and Moises Sepúlveda. Can you speak to the collaborative process working with those filmmakers?

These fellow filmmakers you mention were great. I definitely capitalized on their experience and stole as much as I could from them. Me and Moisés originally brought Toscano an idea, and he turned it into a story. And after that we all collaborated a bit more evenly. But the soul of the film is without a doubt a product of Agustin’s sharp sense for drama through spiky dialogues and a sick sense of humor. I feel like I was the one who generally pushed for violence and tension, Moises was the most “political” of us, and was looking for ironic twists through structure and character arcs, and Toscano somehow squeezed all that into the final script.

Music plays such an important role in suspense films. What inspired your music and score choices in “Immersion?” 

The music was made by a very strong upcoming musician called Paulo Gallo. That’s a name you’ll want to remember. His elegance in composing gave the film the weight and general feeling I was aiming for. We started with moods for adding tension through atmospheric sounds, but once that was done, we adventured into mixing it all with indigenous instruments, because we thought that would add to the sense of danger, while viewing “local” lake characters that seemed menacing. What the music ends up doing, however, is slowly moving those infernal indigenous-like drums and horns onto the father’s theme, and with that it helped us narrate the way he becomes beastly, savage even.