In a way similar to Suspiria (2018), the laboured breathing of a dying woman plays across the opening moments of The Undertone (2025): this film is an aural nightmare and no mistake, starting straight away and keeping up that relentless sensory overload throughout.
In a house full of photos and other keepsakes, a young woman called Evy (Nina Kiri) is solely responsible for nursing her mother through the last stages of her end-of-life care. She divides her time between this weighty responsibility and something she can do from home: she co-runs a supernatural-themed podcast, called The Undertone. It’s ‘the only thing keeping her sane’ in a world of illness and loneliness; this is an immensely lonely film. On The Undertone, and in a nod to a recognisable choice of format for such podcasts, Evy takes the role of ‘the sceptic’ to her co-host Justin’s role as ‘the believer’. When he calls to record this week’s show, Justin (Kris Holden-Ried) takes some time out to ask after Evy’s mother, but other than that it’s down to business, which is what Evy apparently prefers. Normality. Structure.
The theme for this week’s show comes as a surprise to Evy: Justin explains that he’s received a selection of ten audio files sent to his email, and his plan is that they can play them on air. With this agreed, Justin starts playing the recordings. It all starts innocently enough: there’s a man called Mike (Jeff Yung) and his pregnant partner Jessa (Keana Lyn Bastidas) and they want to record evidence that Jessa has started talking in her sleep. This evidence is duly captured, but as the recordings go on and as Justin and Evy work through the files, things get steadily more ominous. Perhaps inevitably given his ‘believer’ role, Justin can hear all sorts of masked messages in the recordings, though Evy isn’t so sure and asks to take a second listen, particularly where Jessa begins singing or playing children’s songs; the film digs into something which only ever seems to be just beneath the surface, and that’s the dark origins behind any number of children’s songs, chants, lullabies – you name it. Rest assured, that isn’t where the film starts and ends: this is just one aspect of where it goes next as the podcasters try to piece together what happened to Mike and Jessa.
For Evy, this all seems to be a welcome distraction at first; before too long, you begin to wonder whether she may just be keen to find patterns where there are none because of the chaos of her own life at present. Both of these things could be true; however, what Evy begins to notice is that there are distinct and frightening parallels between what they are uncovering in the recordings and in Evy’s own, fractured life.
Wow, this is grim. It’s already been mentioned that this is a lonely film; more than that, it’s lonely in lots of different ways; it’s a story of compound loneliness, which prepares the ground brilliantly well for what’s to follow. Being a carer is lonely. Watching someone you love die in slow motion is lonely. Evy also has an AWOL boyfriend – we never see him – and even the podcast, her beacon of order and routine, is a remote exercise, just a sequence of voices in her headphones. Being so reliant on these voices, Evy is very vulnerable to them. Through her heightened, anguished perception, we are just as vulnerable to these horrors which are largely heard, rather than seen. There are shades of The Woman in Black (1989) here, as Evy pieces together a story by listening to it (and the house itself becomes complicit in the unfolding, and deeply unsettling story in ways which also feel distinctly similar).
The audio clips themselves are …horrible, just as they should be: there’s just something about being asked to listen for hidden words and meanings – as alluded to in the film – which makes a person suggestible, primed to be scared. Being such an aural horror, The Undertone of course needs to get that aspect right and it absolutely does: not only is it thematically able to riff on longstanding ideas around things like backwards masking, Electronic Voice Phenomena and more recently, creepypasta, but its own surrounding soundscape is suitably all-encompassing and unsettling, too. Then there’s Evy’s mother, her breathing turning more and more into a ‘death rattle’, a presence in the house, but unable to take part in life. Bookending all of that is the film’s use of silence, which is itself something terrifying. As sensory films go, this one is pitch perfect, riddled with unease throughout – and it’s no slouch on the visuals, either: there’s just enough here, with great use of darkness to further that suggestibility. The film also manages to render something like a simple image search for an urban legend into a fundamentally repulsive inclusion.
As this film made such a personal impact on this reviewer, I’m going to abandon the second and third person here: this film got under my skin. It did for me what Longlegs (2024) – which arguably has some similar aspects and visuals – failed to do; The Undertone engineered my brain into a state of primal fight-or-flight and hypervigilance, by getting the small stuff very right, offering up a fantastic performance from Nina Kiri and the supporting cast, and by allowing its bigger picture to come through in good time. There are also lots of complexities to unpick around faith, motherhood, childhood and guilt – particularly guilt, and of course there were vital choices to make on how to resolve all of this in the film’s perfectly-paced and modest runtime, but The Undertone gets that right too. See what you think, but my advice is to suspend your disbelief and go with this perfectly-curated abject terror, a film which feels very up-to-date, but also timeless. This is director and writer Ian Tuason’s first feature, let alone his first horror feature, so if this is anything to go by, then this promises a director with an instinctive understanding of what makes people tick.
The Undertone (2025) recently featured at the Fantasia International Film Festival.