Birds of a feather dissociate together.

There’s something wrong with the mountains. The air’s too still, the smiles too symmetrical, and the birds seem to know things they shouldn’t. For Gretchen, freshly uprooted to a luxury resort in the Bavarian Alps, it’s not homesickness that keeps her up at night – it’s the feeling the walls are keeping tabs. And her half-sister’s silence isn’t just awkward. It’s tactical.

Seventeen-year-old Gretchen (Hunter Schafer) arrives in the aftermath of her mother’s death, steered into scenic isolation by her distant father (Marton Csokas), his new wife, and the unsettlingly mute Alma. The resort is mid-renovation, a project helmed by Herr König (Dan Stevens) – a smiling cipher with the unsettling charm of a self-satisfied algorithm. When König offers Gretchen a desk job to pass the time, things unravel fast: guests fall inexplicably ill, night brings noises that don’t sound human, and reality begins to twist, as though the resort has its own agenda – and Gretchen’s a cornerstone of it.

Cuckoo pitches itself as a mystery but plays like a body-snatched coming-of-age story – a survival tale built from borrowed parts and stitched expectations. Writer-director Tilman Singer blends sci-fi horror with a soft-lit, anaesthetised aesthetic: a world of pastel walls, resort uniforms that look screen-printed, and people who seem more programmed than employed. The uncanny creeps in quietly, not through gore or jump scares but through implication – the way Gretchen’s own body begins to betray her, her autonomy eroded not by violence but by paperwork and polite insistence.

Schafer is superb: guarded, present, and never performing victimhood for the camera. Her Gretchen is a person first, not a trope – alert, emotionally in flux, and increasingly unwilling to be shaped by anyone else’s narrative. She’s particularly effective opposite Stevens, whose König operates like a management consultant for the uncanny. He doesn’t threaten. He onboards. And somehow that makes him more terrifying.

The plot doesn’t hinge on revelations so much as revelations refusing to matter. There are no earth-shattering twists, just a tightening grip – a slow, insinuating pressure for Gretchen to fold herself into a family structure she never agreed to. Her connection with fellow guest Ed (Sofia Boutella) offers a flicker of warmth, but the film doesn’t sentimentalise it. This isn’t about love in the face of horror. It’s about horror as a function of love denied, deferred, or misused.

Alma, meanwhile, occupies the strange middle ground so many genre hybrids botch. She’s not a warning or a weapon – just a quiet refusal to conform. Her silence is never exploited for drama. It’s a stance. A rare moment of trust in the audience’s ability to sit with ambiguity without needing it resolved or rationalised.

Singer isn’t interested in explaining the mechanics of the horror. What Cuckoo offers instead is dread by accretion – a slow takeover of selfhood, until even resistance becomes ritualised. Escape isn’t a climax, it’s a procedural delay. The film’s most haunting idea isn’t that something wants to hurt Gretchen. It’s that something wants her cooperation.

It’s hard to say who the film ends up siding with, but maybe that’s the point. It’s not about who’s right, it’s about who’s left. And Cuckoo leaves its survivors exactly where they need to be: together, imperfect, and finally out of earshot.