Undertone Review: This Podcast Horror Movie From A24 Is Genuinely Scary

I love horror movies, but I'm very rarely scared by them. Not because I'm particularly brave, but rather because I've spent so much of my life watching horror movies that I've built up a tolerance. I'm desensitized to things that go bump in the night. But every now and then, something breaks through and gives me the creeps, like Ian Tuason's exceptionally scary debut "undertone," a new fright flick from the folks at A24. Using impeccable sound design and making great use of negative space, Tuason's stripped-down film builds a continuous amount of dread as it creeps along.

If there's an overall problem with what Tuason is doing here, it's that his script isn't terribly original. Recently it was announced that the filmmaker was hired to reboot the popular "Paranormal Activity" franchise, and there are long chunks of "undertone" that feel like the director's audition tape for that gig. Throw in a little "Sinister" mixed with heavy creepypasta influences, and you've got yourself a film that feels more than a touch predictable. 

And yet ... "undertone" is so good at getting under your skin that I was willing to give these slightly derivative touches a pass. If you're looking for a scary movie that's actually scary, "undertone" delivers. If you're a horror fan, you've seen this sort of story told before, but it's rarely told this well.

Evy (Nina Kiri) co-hosts a popular paranormal podcast called "The Undertone." The show dabbles in online urban legends and supposedly true ghost stories, but Evy is skeptical while her co-host Justin (Adam DiMarco) seems to be a true believer. Evy is currently puttering around the house of her dying mother (Michèle Duquet), and it's clear she's been there for a while because she's set up a makeshift podcasting studio at the dining room table. "undertone" never leaves this house, and Evy and her seemingly comatose mom are the only characters we ever see on screen, which makes the entire movie feel both intimate and claustrophobic. Tuason apparently shot the film in his parents' house, which only adds to the atmosphere. This doesn't feel like a set; it feels like the slightly out-of-date home an elderly parent has occupied for a long, long time.

Evy's mother was clearly devoutly religious when she was still on her feet, as her house is choked with Catholic iconography. Tuason understands that anyone who has grown up in a house littered with such holy tchotchkes knows exactly how creepy and ominous they can all seem when it's late at night and the lamps are dimmed. (My own mother used to have a painting of Jesus hanging above our entryway door, and late at night, the Messiah's eyes seemed to follow you around the room).

The presence of a dying parents and the spectre of being smothered by faith made me think "undertone" would follow in the footsteps of so many recent horror movies and be all about trauma. To be clear, I'm not against using trauma in your horror story, but it's become a kind of lazy shorthand for so many modern fright filmmakers. Refreshingly enough, "undertone" is simply using these details as window dressing; they color the movie but don't inform it. Some may take issue with this and feel like Tuason hasn't made the most of the themes he's touching on, but I think the film handles them just right.

Things kick into gear when Justin reveals he's received a mysterious email containing ten audio files. After listening to part of the first file and realizing it's potentially creepy, he's deliberately avoided playing the rest, and wants to listen to them one by one with Evy while recording a new episode of their podcast. Evy is game, and as the two start listening to the files, the story of an unseen married couple begins to take shape. The husband on the recordings says his wife has been talking in her sleep but she doesn't believe him, so he's going to start recording through the night to prove herr wrong. You can probably guess what's going to happen: some bad stuff is going to get captured on these recordings, and every fiber of our being will want to practically scream at Evy and Justin to stop listening before it's too late.

"Two people listen to spooky audio files" doesn't exactly sound like the most thrilling cinematic experience, especially when we only ever see one of those people. And yet, "undertone" manages to create a true sense of horror thanks to Kiri's sympathetic lead performance — we really worry for her as things start to go very, very wrong — impeccable audio design, and a great use of shadow and space.

Director Tuason and cinematographer Graham Beasley will frequently frame Kiri's Evy off-center, with the darkened open space of the house looming behind her. This negative space draws our gaze because we've been conditioned to expect something to pop up in there. When Evy puts on her noise-canceling headphones, all the sound of the room drops away, cocooning us into Evy's headspace. I saw the film in a Dolby theater, and I highly recommend you do the same, as the finely-tuned audio system made the film's frequently unnerving soundtrack even more powerful.

To enhance the horror, "undertone" draws on the type of fears and superstitions that have risen to prominence in the internet age. As the film begins we learn about a supposedly cursed YouTube video that kills anyone who watches it. Later, the podcast hosts dive into hidden subliminal messages in children's nursery rhymes (played backwards, of course). And just for good measure, we learn about a baby doll that whispers creepy stuff when you pull its string. 

These are the types of horrors that have become ingrained in internet culture; the type of urban legends that first started on school yards before migrating to the web as message boards became popular. The familiarity is a feature, not a bug, because we've all heard (or read) online legends about these sorts of things. It effectively draws us into the world of the film and makes it feel all the more, well, real.

"undertone" is in no hurry, burning out its scary story like a candle melting away during a long, dark night. Which is why the film's bombastic finale feels slightly unnecessary. To be sure, Tuason does a magnificent job ramping up the nightmare fuel and creating a series of scenes that feel designed to give you a panic attack, but it almost feels like too much for such an otherwise subtle experience. No matter: "undertone" is so effectively spooky that I found my eyes nervously darting to shadows as I walked to my car after the screening. The best horror movies don't need cheap jumpscares, they just need to make you feel like something dreadful is out there, lurking, waiting to make itself heard.

/Film Rating: 8 out of 10

"undertone" opens in theaters on March 13, 2026.