Children are fodder for some of the best horror cinema ever made. The genre thrives on making the ordinary unfamiliar, after all, and what could be more normal than your own children? They are expressed as innocent and vulnerable across our culture, more than ever in horror movies where they regularly become the target of the violent, the murderous, or the frighteningly supernatural. Inverting that trope leads to some genuinely provocative stuff: if protecting your child from evil generates rich levels of tension, what about being threatened by your child?

Eskil Vogt makes a powerful contribution to the genre with The Innocents, a 2021 Norwegian thriller in which children living in a blandly ordinary housing estate begin to exhibit psychic powers. It is a slow film – deliberately so – and gradually builds tension with stillness, rising dread, and provocative moments of violence.

The film follows Ida ( Rakel Lenora Fløttum), a sullen nine year-old forced to move house to the outer suburbs of Oslo. Her sister Anna (Alva Brynsmo Ramstad) is on the autism spectrum, and communication with her is difficult. Ida soon befriends local kids Aisha (Mina Yasmin Bremseth Asheim) and Ben (Sam Ashraf) – only for both of them to begin developing telepathic and telekinetic powers, with frightening consequences.

There is a challenging conceit at the centre of The Innocents, involving Ben’s growing powers and malicious intentions. Plenty of horror films have shown well-intentioned children turn evil via possession, undead transformations, or something similar. Vogt’s film begins with a child who is already bad: Ben is resentful, violent, and actively cruel to animals (people averse to seeing pets suffer harm should be forewarned). What drives much of the film’s horror is not seeing a child turn monstrous, but rather the potential for harm should an already-monstrous child suddenly be capable of causing genuine and traumatic damage. I suspect different viewers will begin feeling unsettled by Ben’s growing powers at different points in the movie, but sooner or later that queasy feeling drops and drives this patient, deliberate narrative.

There are imperfections. Vogt is on shaky ground throughout when it comes to Anna, whose combination of autistic traits and growing powers of her own reeks of an awful cliche. Popular representations of autism spectrum disorder regularly portray characters with low-functioning social skills and amazing mental abilities. The treatment of Anna here works, but only in a kind of narrow-eyed and suspicious manner. It feels just a little bit too awkward.

The juvenile performances are excellent, and very effectively directed. The film is almost entirely positioned from a child’s point of view, and that adds immeasurably to its sense of growing panic. This kind of quietly developing dread is marvellous when executed correctly, and Vogt demonstrates a skilled hand at it. The Innocents strikes me as the year’s first runaway horror success.