The Undertone” Is the Scariest Film of the Decade—A Relentless, Nerve-Shredding Descent into Pure Terror

Horror has been thriving in 2025, shattering box office records—and the gas pedal isn’t letting up anytime soon. While covering the Fantasia Film Festival remotely, a few of my mutuals urged me to check out a small indie called The Undertone. Little did I know I was about to watch what might genuinely be the scariest film of the decade—an unrelenting assault on the senses that leaves you paranoid and shaken to your core.

The Undertone follows Evy Babic (Nina Kiri), host of a popular “all-things-creepy” podcast, who moves into her dying mother’s (Michèle Duquet) home to serve as her primary caregiver. Alongside her co-host Justin (voiced by Kris Holden-Ried), Evy receives ten mysterious audio recordings from a young pregnant couple plagued by unexplained paranormal disturbances. As she and Justin dig deeper, Evy begins to suspect the woman’s harrowing tale is more than just a story—and something far more sinister lurks beneath the surface. With each new recording, the line between reality and nightmare blurs, chipping away at her sanity.

What makes the film so effective is its seamless fusion of Graham Beasley’s atmospheric cinematography, David Gertsman’s immersive sound design, and Ian Tuason’s assured direction. The audio work is so immersive that you can’t always tell if the sound is coming from the speakers, from inside the theater, or from the seat right next to you. Certain noises and whispered phrases will make the hair on your arms stand up. The cinematography amplifies the dread, using long, lingering shots of Evy against oppressive darkness. You find yourself questioning—Is there something in those shadows, or is it the film playing tricks on you? Not since The Descent have darkness and the unknown felt this menacing.

The film’s impact ultimately hinges on Nina Kiri’s phenomenal performance in what is essentially a one-woman show. She delivers a gripping emotional range that keeps you locked in from start to finish, pulling you into Evy’s unraveling mind. Kiri and director Ian Tuason create an atmosphere so tangible it feels like you’re in the room for a live taping of the podcast.

When The Undertone hits theaters, it’s a film that demands to be experienced with a crowd. Like The Blair Witch Project, Paranormal Activity, and The Conjuring, it has the potential to define a generation’s nightmares. This is a rare, deeply unsettling work of horror that will have you questioning reality right up until the final tape plays.

5 Seths out of 5