‘Undertone’ Review – A Sensory Masterwork In Escalating Terror & Dread

There is something to be said about a film that rewards your patience. Often referred to as a slow burn, it’s a gradual buildup to a payoff that makes all the waiting worth it and allows all the pieces to come together to form a terrific, cohesive experience. This is what takes place with A24’s latest horror release, Undertone, written and directed by Ian Tuason in his directorial debut. Across various reviews, you’ll be told about its immersive sound design, and let it be known that this is no mere gimmick. This is sensory overload in the best way, where you’re put within the sonic landscape of the film and allowed to let every ounce of the fear seep in. What’s also impressive is what happens during moments of complete silence. You’re so immersed in the film’s haunting atmosphere that even the silence feels like a threat, gradually creeping to the surface. It has been a while since a horror film has lingered with me this way, and it’s one that I haven’t quite been able to shake.

Evy Babic (Nina Kiri) is the co-host of a paranormal podcast alongside her friend, Justin (Adam DiMarco), where the setup for their show is perfect for discussions about the other side and their validity. Evy is a pure skeptic, while Justin is a believer in the paranormal, but after Evy has to move back home to take care of her dying mother (Michèle Duquet), the podcasting duo is sent recordings for their show from a married couple experiencing paranormal phenomena in their home. As they dive into these recordings, Evy draws closer to becoming a believer as the sounds from these tapes push her further into escalating paranoia and terror.

The less you know about Undertone, the better. The shocks are meant to surprise, and one should be able to experience this level of fear firsthand. One of the masterstrokes of the film is that the only characters shown on-screen fully are Evy and her mother, with the camera lingering almost uncomfortably primarily on Evy. The rest of the characters, including Justin and the sounds from the recordings, are all off-screen voices, which allows for the audience to be fully immersed in Evy’s sensory experience. Not only does this amp up the fear due to the film’s immaculate sound design, but it also creates a sense of growing isolation as Evy’s paranoia and fear from what she’s hearing creates an unnerving level of claustrophobia.

Nina Kiri has the task of essentially being the one human element that carries the film. She’s the face the audience sees from frame to frame, although there are occasional glimpses of her mother. Physically, her mother is present, but she’s so near death that Evy is practically alone in the house. Her supporting cast, albeit in a very unusual sense, is the sound design and voices that she hears along the way. Personally, I was unfamiliar with Kiri’s work before this film, although I was aware she was a fan-favorite on the Hulu series The Handmaid’s Tale. As this was my first experience with her work, I was blown away by how emotive she was as an actress, as she conveys Evy’s emotions throughout the film. This goes beyond sleep deprivation and stress. Evy is being ripped apart by paranoia as she dives deeper into the voices and sounds that she can’t shake. Kiri makes you feel like you’re in this with her, and that’s a combination of her stellar performance and Tuason’s choice to keep the focus on her as the sound becomes almost unbearable to take.

Undertone is immersive in the best way. Having experience as a podcaster myself, the way that the outside world is cut off once the headphones are placed on is expertly replicated here. Every sound within the house is blocked out, and all we hear are the voices within her headphones. Sometimes it’s pleasant, as is the case during some early podcasting banter with her co-host Justin, and other times it’s downright terrifying as she is drawn into the ten recordings sent her way. Because of how this is all set up, it’s easy to feel as if we’re listening with Evy, which makes the experience equal parts intimate and unnerving. This is primarily why the film remains with you long after it’s over. The voices that Evy hears become the voices the audience is hearing in their heads, and it makes it nearly impossible to shake them off.

Then there are the moments when the audience is waiting patiently for the next fright. Yes, Undertone is a masterclass in sound design, but it’s also visually arresting, as some of the images are also haunting to the core. For a film made on a reported $500,000, it doesn’t look like it. There is limited space to work with and one primary performer, but there is a polish to Undertone that allows it to look sleek enough without diminishing any of the style necessary to maintain the film’s sense of closed-in space.

One element of the film that did surprise me, because I didn’t expect it, was how it could turn things from our childhood into something completely unsettling. Fairytales and nursery rhymes have always had a hint of creepiness to them because their origins are really warnings wearing the mask of sweet tunes that are used to put children at ease. Undertone dives into the darkness of these melodies and makes it clear that even if you heard these lullabies as children to drift you into sleep, there is no denying that the soul of these songs could very well be evil and full of malicious intent.

Despite Undertone’s genius at play, this is bound to be a polarizing horror film. Given the fact that early word was this is “the scariest movie you’ll ever hear,” it builds up a considerable amount of hype that is near impossible to live up to. It’s almost guaranteed that while some will have my experience with the film, others will not appreciate the gradual way that it builds to its scares and ultimate conclusion. However, if you give the movie an honest shot, it will reward your patience in the end, and please be sure to experience this in a theater. This is not just a cry for the theatrical experience; it’s a necessity with this film. You are meant to feel this movie in your bones through the best surround sound possible, because this kind of depth can’t really be experienced at home, even with the best system. Undertone is a horror film meant to reach into your nervous system and never let go. A sensory exercise in fear that proves the less you see, the scarier it is.

Undertone will debut exclusively in theaters on March 13, 2026, courtesy of A24.