Director Darren Lynn Bousman began his feature filmmaking career by directing the first three sequels in the mega-popular Saw series. Between his distinct style and his work on that series, Bousman became the perfect person to revive a subgenre we didn’t know we needed; the gritty nunsploitation. In St. Agatha, Bousman unleashes vicious nuns upon unsuspecting young girls in need, with terrifying results.

Set in 1957, St. Agatha follows Mary, a young woman with a dark past who also happens to be unmarried and pregnant, a bit of a taboo for the time period. With nowhere left to turn, she finds herself directed to a nearby convent for support. It’s a looming home right out of a gothic nightmare, led by Mother Superior, and Mary soon discovers that the strict rules employed by these nuns are anything but holy. The pregnant girls in Mother Superior’s care live in constant fear, and breaking any rules, however minuscule, comes with violent punishment.

Washed in blues and oranges, Bousman’s vision begins as an almost ethereal dreamscape before descending into a nerve-fraying nightmare. His use of silence, with only the squeaks and creaks of the old house, builds for some taut, uncomfortable tension. Mary’s story cuts between her haunted past, slowly unspooling what led her to her current convent prison, and her frightening present. While the motivations behind Mother Superior’s plans for these pregnant young women might be guessed long before its reveal, the journey getting there is every bit unpredictable as it is petrifying.

Sabrina Kern makes her feature debut as Mary, and what a debut she makes. The protagonist is put through the ringer, suffering torture that makes James Caan’s romp with Kathy Bates in Misery look like a trip to Disney World. That’s only the physical aspect, the emotional trauma from Mary’s past combined with the guilt of her actions affecting her roommates adds a whole new hefty weight to the character’s shoulder. Kern carries the heavy weight of the role with ease. To Kern’s empathetic protagonist is Carolyn Hennesy’s Mother Superior, an icy villain that would terrify even Jigsaw himself. Hennesy is hands down one of the most horrifying horror villains to come along in a while, and her underling nuns only enhance her cunning, ruthless power.

Even with the immeasurable talent of Kern and Hennesy at the forefront, St. Agatha is filled a roster of talented women. The ruthless nuns working for Mother Superior don’t have much dialogue, yet convey a depth of calculated hatred with their physicality. Hannah Fierman (V/H/S, SiREN) is also a standout as one of the girls living at the convent, her character journey is heartbreaking and satisfying, and the actress is one clearly on the rise.

Even though Bousman has toned down the torture from his Saw days, he still has a strong grasp of eliciting audience reaction, and is surely not afraid of putting his characters through the ringer. There are some graphic moments of extreme brutality, but they punctuate a long drawn out cat-and-mouth game of psychological warfare that brings the true fear. If you didn’t have a phobia of nuns before, this might cause it.

Truthfully, there’s not much to St. Agatha, and the motivations behind the convent can easily be construed before the final showdown. None of that really matters though, because it’s such an engaging thrill ride full of shocking moments and fulfilling character arcs that it’s absolutely worth watching. Kern and Hennesy deliver powerhouse performances that leave you gripping your seat and holding your breath. Bousman knows how to ramp up the tension in measured strokes, barely allowing the audience time to gasp for more air. His nuns are brutal in the most exploitive way, finding grisly new ways to torment their wards that don’t involve gore (though gore is plenty). If your gag reflex is strong, prepare to get tested with St. Agatha. Bousman’s latest is a remarkable, gritty nunsploitation that we didn’t know we needed, and I hope it’s a sign of more to come.