Grainy VHS footage has become a popular trope in the horror genre for years, with its deteriorating quality often enhancing the impression of an ominous, otherworldly realm on the verge of collapse. (The appeal of the entire anthology horror series “VHS” is steeped in this effect.) Yet “Censor,” the engrossing first feature from British director Prano Bailey-Bond, may be the first of its kind to put the VHS horror phenomenon in historical context. The story of a troubled British film censor circa 1985 eventually settles into the kind of subjective descent into lunacy the genre’s offered up many times before, but there’s a certain immersive thrill to the way this character’s unraveling takes place within the same dilapidated material she’s been forced to watch for her job.

“Eye gouging must go!” So writes Enid (Niamh Algar) in the opening minutes of “Censor,” going about her routine of jotting down the most egregious, gory moments from the movies placed in front of her and determining which ones cross the line. From there, Bailey-Bond and co-writer Anthony Fletcher build out an immersive backdrop: It’s 1985, Thatcher-era Britain, as a paranoid society assumes that censors must guard the children from the terrors that movies offer up. But who’s looking out for the censors in all this? Enid takes her guardianship seriously, but has nowhere to put the images at the end of the day, and soon they intermingle with her own dark past. At first, the movie unfolds with elegant atmospheric dread, as Enid contends with a brutal, male-dominated work environment in which her opinions rarely hold weight. When a lunatic murders his family in a manner based off one of the movies she was forced with cutting down, the world turns against her. It doesn’t help that she’s already got plenty of additional baggage to sort out, since her sister vanished decades ago and her parents are ready to declare her dead, against Enid’s wishes. That’s when she sees a particularly unnerving exploitation movie called “Don’t Go in the Church,” with an opening slasher bit featuring an actress that bears an unmistakable resemblance to Enid’s missing sibling. At least, that’s what Enid thinks, as she journeys down a rabbit hole of theories and detective work that may or may not hold together. Laced together with eerie sound design and sleek imagery that slowly gives way to the VHS filter, “Censor” suggests an innovative blend of Peter Strickland’s giallo homage “Berberian Sound Studio” and “The Ring.” It’s also a clever entry point to the world of “video nasties,” those lo-fi and usually grisly horror efforts that circulated in shady rental stores on VHS beyond the censors’ purview. When Enid finds her way into one, seeking to dig deeper into the mystery director’s work, “Censor” evolves into a canny meditation on the subversive desire to look exactly where society tells us we shouldn’t.

Needless to say, she goes for it, binging on the oeuvre of an enigmatic and seemingly twisted figure named Frederick North (Adrian Schiller) as she strengthens her suspicions that he might have something to do with her sister vanishing ages ago. The clues never quite add up, but they become increasingly irrelevant as “Censor” foregrounds the way Enid confuses her paranoid delusions for detective work. Grimy horror movies have drilled themselves into her brain so deep that they’re all the clues she needs. Ultimately, her path to madness works well enough as a subtle meditation on trauma and grief, guided to a large degree by Algar’s stern and studied performance as a woman seeking answers from the only tools at her disposal. By the time she ends up stalking a leering producer (a slimy Michael Smiley of “Kill List” fame), “Censor” makes it clear that Enid has gone past the point of no return, and then takes her a few steps further. The wild closing moments, a mashup of brutal vengeance and delusions that complete the transition into grainy mayhem, rush past so long it’s a wonder why the movie didn’t give them room to breathe. “Censor” ends on a spooky note of ambiguity that feels so inevitable it’s almost as if everything leading up to it was an afterthought. But once it gets there, the movie shows the mark of a filmmaker in full command of vintage horror’s most disturbing strengths — and well-equipped to resurrect them.

Grade: B

“Censor” premiered in the Midnight section of the 2021 Sundance Film Festival.  As new movies open in theaters during the COVID-19 pandemic, IndieWire will continue to review them whenever possible. We encourage readers to follow the safety precautions provided by CDC and health authorities. Additionally, our coverage will provide alternative viewing options whenever they are available. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.