It’s rare for a movie to get technology right. And it’s even rarer for that movie to be a thriller or horror, where realism takes a backseat to scares and tension. But Red Rooms mostly gets it. Nothing takes me out of a film quicker than a tech MacGuffin that might as well be literal magic. Yes, the phrase “dark web” will always sound a bit silly, but at no point during its 118 minutes does the tech become a distraction.

It’s not the tech that makes Red Rooms great, though. It’s just something that could have easily tanked an otherwise excellent movie. What carries the film is the expert tension building by director Pascal Plante. The perfect slow-burn pacing. And the incredible performances by Juliette Gariépy as Kelly-Anne and Laurie Babin as Clementine.

The film centers mostly on Kelly-Anne, a model / hacker / professional gambler who attends the trial of serial killer Ludovic Chevalier. She befriends Clementine, a fan of Chevalier who insists that he is being framed.

Clementine neurotically and loudly defends Chevalier, calling into TV shows and shouting at reporters outside the courtroom. She makes a spectacle of herself. But Kelly-Anne remains more mysterious, her motives unclear. Even at the end of the film, there is ambiguity about what she was trying to accomplish and why.

The ambiguity is part of what makes Red Rooms so enthralling. The movie feels unpredictable. None of the characters seem trustworthy or relatable. The world they inhabit is familiar, yet uncanny.

The movie lingers in that discomfort for long periods of time, making you squirm. Giving you the opportunity to play through all the possible scenarios that could play out in your head. Is Chevalier really the killer? Is Kelly-Anne the killer? Was one of the victim’s mothers an accomplice? Is the prosecutor keeping a secret?

The movie inches along, drawing out a tale of kidnapping, live-streamed torture, and snuff films before erupting into a climax that unexpectedly mines online poker and Bitcoin for legitimate drama. It’s ultimately less about the murders themselves than it is about obsession, internet bubbles, and the media. It almost feels like a grimier companion piece to David Fincher’s Gone Girl.