Undertone (2025) Review

The most important and most relatable thing about Undertone is how it plays on that feeling we all get when we’re alone… in the dark, late at night, when we start to hear unsettling things.

It’s that really disconcerting silence at three o’clock in the morning. Fridge humming in the next room. Pipes ticking. Someone upstairs breathing. Undertone understands that unmistakable feeling and weaponises it. Within fifteen minutes of watching I found myself staring suspiciously at the dark corners of my own living room like an idiot, which is usually a fairly reliable sign that a horror film has got under my skin.

Ian Tuason’s debut is, on paper at least, almost absurdly minimal. A podcaster named Evy, played with frayed intensity by Nina Kiri, has moved back into her childhood home to care for her dying mother. The house is full of painful memories and out-dated decor. Setting up downstairs, she records a paranormal podcast with her unseen co-host Justin, who shares a series of disturbing audio files involving a couple apparently haunted by something ancient and malignant. The more they listen, the worse things become. That’s essentially it. One house. One visible lead performance. Voices through headphones and lots of creeping dread.

And really, it shouldn’t work this well.

The obvious comparison point is Paranormal Activity, although Tuason’s film feels less interested in jump scares than in slow psychological erosion. The horror in Undertone comes from accumulation. Strange noises looping over and over. Nursery rhymes played backwards. The soft hiss of static. The way Evy gradually stops trusting the house around her, then herself. Even a dripping tap soon sounds like the unstoppable footsteps of a terrifying fate.

What impresses most is the confidence of the filmmaking. Tuason resists the urge to over-explain almost everything. Modern horror has developed a bad habit of eventually stopping dead so somebody can deliver a ten-minute lore lecture about demons and trauma and inherited grief. Undertone skirts dangerously close to that territory a couple of times, particularly once the mythology surrounding Abyzou starts surfacing, but mostly it trusts atmosphere over explanation. It then uses a podcast phone-in to reveal details in real-time.

The film behaves like a nightmare as details blur together and threads remain unresolved. Things happen because they feel frightening rather than because they neatly complete a screenplay diagram.

Some viewers might leave the film a little annoyed by the fact that it refuses to tie its ideas together with tidy logic. But then horror rarely benefits from excessive clarity. The more you pin fear down, the less frightening it becomes. Some of the ideas are a little paranormal horror playbook, but the novel emphasis on the aural and the use of shadowy voids in the framing of shots makes this a dreadful treat for the eyes and ears.

Kiri carries the entire thing brilliantly. It’s a performance built around listening rather than reacting. Leaning forward, holding breath and trying not to panic. You feel the exhaustion hanging off her because, for most of the film, you’ll feel the same way. Caregiving horror is becoming its own subgenre at this point, but Undertone taps into something painfully recognisable about isolation and guilt without turning those themes into capital-I Importance.

And the sound design really is extraordinary. Not flashy or constantly aggressive. Just horribly immersive. There’s an extended blackout sequence near the end which reduces the film almost entirely to noise and suggestion, and it genuinely makes the hairs on your arms stand up. Soon you become hyper-aware of every tiny sound around you. Every scrape. Every whisper. Every sudden absence of noise.

Undertone feels less like watching a horror film and more like accidentally overhearing one through the walls. It gets under your skin in a way that many louder, bloodier horror films could never manage.

Movie Rating:

Undertone trailer