Undertone immediately made waves following its premiere at Fantasia International Film Festival in 2025, quickly lauded as one of the scariest films of the fest and a must-see as soon as genre fans could get their eyes – and ears – on it. Ian Tuason’s hotly-tipped feature debut soon made its way to Sundance and was picked up by A24, further adding to its buzz. Now enjoying its theatrical run, Undertone is a nerve-shredding auditory experience that will bore into your brain and haunt you long after the credits roll.
The single-location horror film focuses on Evy (Nina Kiri), a woman who hosts the Undertone podcast with her friend Justin (Adam DiMarco), in which she is the sceptic to his believer. She records the episodes from her childhood home, where she has moved to act as caregiver to her dying mother (Michèle Duquet). The duo is sent recordings of a married couple (Keana Lyn Bastidas and Jeff Yung) experiencing terrifying noises and phenomena in their home, listening and reacting while they record. While reviewing mysterious audio files, Evy begins to notice terrifying parallels within her own life.
Undertone’s hook lies in its simplicity, with one character in one location listening to recordings and experiencing increasingly eerie phenomena, from bumps in the night to creaking doors. It’s a classic haunted house tale with a thoroughly modern twist, as ghosts in the wires break into the real world and threaten to take the most vulnerable in society. The narrative does become somewhat convoluted in the threads it attempts to juggle, but when it strips everything back and focuses on its blood-chilling scares, Undertone lives up to its marketing promise of being “the scariest film you’ll ever hear”. Tuason expertly builds tension from start to finish, never giving the viewer chance to relax as it hurtles towards its nerve-shredding final act. Every detail littered through the narrative is pulled together in a satisfying conclusion, layering fright upon fright to almost unbearable effect. While Undertone sometimes wanders off beat, it is a testament to the power of storytelling, frightening you long after viewing.
The use of sound fully immerses the viewer into the horror, with Tuason creating an auditory hellscape that puts you right into the shoes of the podcast hosts. Undertone works perfectly both in a state-of-the-art cinema and streamed at home through headphones – in the dark, of course – offering a fresh, yet still terrifying experience each time. Kiri carries much of the chaos of Undertone in her incredible performance, commanding the screen at all times as she grapples with the impending death of her mother, learning she is pregnant, and the supernatural horrors unfolding in front of her. She brings to life the burnt-out podcast host escaping into the world of ghosts and ghouls to shut out the trauma of her own life without relying on familiar tropes horror fans will have seen time and time again, compounding the events she is living out before our eyes.
Undertone is a nightmarish descent into madness and an impressive feat of storytelling. Despite being rough around the edges in parts, Tuason’s feature debut ramps up the terror with the simplest of frights, thanks to his expert grip on the central demon’s lore and the story unravelling in the recordings. Undertone is at its best when it goes back to basics, creating some of 2026’s most terrifying sequences with some of the most simplistic set pieces, noises, and reactions from Evy. It shifts and changes with each disturbing revelation, with varying success, in a unique way that is sure to usher in a slew of imitations.
UNDERTONE is in cinemas now. You can read our interview with Ian Tuason and Nina Kiri here.
