The very concept behind Inside directors Alexandre Bustillo and Julien Maury’s latest is simultaneously ingenious and daunting. A haunted house that can only be accessed by diving to the bottom of a murky, deep lake exhilarates for its innovative new spin on the subgenre. Yet, the technique and precise, painstaking execution required to bring this ambitious aquatic nightmare to life seem like, well, a nightmare. While the nature of bringing this vision to the screen does limit it narratively, The Deep House more than unsettles through an eerie, otherworldly atmosphere and an exhilarating new twist to the haunted house.

Urban explorer Ben (James Jagger) is a thrill seeker in perpetual pursuit of the next unique find that will draw big numbers on his social media channels. Ben’s latest goal is to find legendary village ruins submerged deep underwater fifty years ago during a dam’s construction. He drags his girlfriend Tina (Camille Rowe) along, constantly pushing her past her comfort zone and refusing to slow down. The couple happens upon a local, Pierre (Eric Savin), who promises to show them the coveted spot that isn’t on any map. With the instructions of “follow the steps” down 50 meters below to the dark depths of the lake and only an hour or so worth of oxygen, Ben and Tina find leaving their discovery might prove harder than finding it.

D.P. Jacques Ballard’s extensive experience with underwater cinematography is The Deep House’s most significant and vital asset. As Ben and Tina make their descent into darkness, to eventually discover a pristinely preserved home where no fish dare come near, it’s Ballard’s cinematography that creates an eerie, elegant atmosphere that never relents. That atmosphere of preserved bodies or home décor lifelessly floating in the abyss engages visually where the narrative sags.

The technical precision and safety measures required of having actors and crew underwater means a scaled-back story; it’s simple mythology. The scares don’t come as fast or furious as many would probably like. Blocking a scene is tricky enough on dry land, but underwater? It’s a technical marvel. That means a slowed sense of movement, too; it takes Ben and Tina a while of careful exploration before the activity escalates. But Bustillo and Maury give enough story details to keep things interesting, followed by a post-credit scene that further clicks the mythology into place. When the scares do come, they’re effective, even though some are obscured by frenzied camerawork in panicked moments.

Jagger’s Ben might also frustrate viewers. His unwavering focus on his career and achieving the next big find for numbers means he’s not the most likable, especially in the context of his relationship. Tina feels pressured to meet Ben on his level, and that lack of experience complicates matters. Jagger also isn’t the strongest of performers, which undermines the film’s climax in parts.

The Deep House offers a slow, dark descent that builds to a satisfying conclusion. The underwater setting gives an otherworldly, eerie quality unlike anything else and makes the house’s ghosts all the more startling. It’s more content to let the current slowly wash over its audience than provide a sensory assault, so enjoyment will likely vary depending on how well you’re willing to submerge yourself in the details over the simplified story. But Bustillo and Maury successfully blend two subgenres that couldn’t be further apart and execute it with impressive ambition. That daring ability to test the bounds of horror, at least on a technical level, is always welcome in the genre space, even if not a perfect success.

There are no shortcuts here. It’s as practical and tangible as possible. And it makes for one of the most remarkable and memorable haunted houses in recent memory.

The Deep House will premiere on EPIX on November 5 and will also be available for digital purchase from Paramount Home Entertainment on the same day.