The horror genre has always been scrutinized for its relationship with onscreen violence, but movies about serial killers, especially real ones, merit extra attention. These anomalous criminals have an outsized presence in fiction, and indeed in the popular imagination. Sometimes they are deployed as compelling, formidable villains and nothing more, on par with any other horror monster. The best serial killer stories, though, are more interrogative — of the institutional failures that create and enable them, the social forces that mythologize them at the expense of their victims, and the obsession that drives their pursuers.

Place undue focus on the violent acts, or on the killers themselves, and a film risks becoming part of the problem. This is the careful line that Ali Abbasi’s Holy Spider walks; it pushes so close to the edge that, to some, it may earn such criticism. But, in the estimation of this critic, the clarity and specificity of the movie’s targets keep it on course, making for a viewing experience as thought-provoking as its narrative is gripping.

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The opening sequence is crucial to understanding Abbasi’s project, and is worth recounting in some detail. Somayeh (Alice Rahimi), whose naked body is spotted with bruises, dresses and leaves her child one night, promising to return in the morning. She is a prostitute in the Iranian city of Mashhad, a holy city. She looks somewhat haggard, soon attributed to opium addiction. The camera follows her as she picks up a couple johns, who use her with little regard for her humanity; one even shorts her on the payment. Then she gets hired by a man whose face is kept obscured. He drives her to a quiet neighborhood and leads her to an apartment, though her unease is palpable. Instinctively, she senses danger, and turns to leave in the building’s stairwell. The man pounces and strangles her to death as the camera watches her face, picking up her choked plea that she has a child. Her killer then carries her body to his motorcycle, dumps it on the side of a road, and drives back to the city, the lights of which eerily resemble a spider’s web.

Ariane Naziri in Holy Spider

This sequence is painful to watch, as it should be. Through this woman, her difficult life, and her cruel murder, all the killings that follow are given the impact yielded by empathy. The so-called Spider Killer is just a presence in the scene, anonymous and malevolent, but he will never be so unknowable again. He is Saeed Hanaei (Mehdi Bajestani): Builder, family man, veteran of the Iran-Iraq War, and Mashhad’s self-appointed cleanser of “impure” women. He becomes very human as the viewer spends half the runtime with him, though anyone who would label Holy Spider as overly fascinated with its serial killer would be too quick to dismiss this opening. From his first appearance, he is coded as a monster, a force of evil, but to leave him with that characterization would afford him unjust grandeur. Saeed is a man, however monstrous his actions, and he is a small man. His claims to piety, to greater purpose, are delusions that hide the petty inadequacies and weakness of character that drive his murders. He desires the glory of martyrdom, and self-mythologizes in the manner of many serial killers. Abbasi’s film, by making him so understood, denies him this.

At the same time, Holy Spider undergoes the same project in reverse with its protagonist, Arezoo Rahimi (Zar Amir Ebrahimi). A journalist who comes from Tehran to investigate the nationally famous Spider Killer case, she is very human from the outset, and faces many challenges as a working woman in the holy city. She chafes against the extra restrictions placed on her, and the tendency of men in power to dismiss, obstruct, and undermine her at any opportunity. But gradually, as she perseveres with the righteous sense of purpose her target can only dream of, she ascends to heroic status. The deeper into the investigation she gets, the more certain she becomes that the police will never catch the murderer — and not because they can’t. She smells a conspiracy where the viewer, afforded access to Saeed’s perspective, knows there isn’t one, but she is pushed ever closer to seeing herself as the only hope for bringing the killing to an end. Much of the dramatic tension, as Saeed’s methodology begins to fray, comes from wondering just how far Rahimi will go to stop him.

Mehdi Bajestani in Holy Spider

Their interwoven narrative strands make for a compelling thriller, but they also work in tandem to serve Holy Spider’s greater political purpose. Rahimi’s experience fleshes out the milieu in which Saeed’s actions will eventually be interpreted. His character development establishes the audience’s view of him, and thus determines their emotional response to how he is viewed by the public. Though the film never loses sight of the victims and their families, it picks up another, less expected focal point in the final act that reveals culture of misogyny as its chief interest.

The harm in policing women’s behavior so severely, both for women and for men, is laid bare, and a moment of non-violence ends up becoming Holy Spider’s most bone-chilling. It is an impressive bit of filmmaking that will leave its audience with strong feelings, most likely inflected by Rahimi’s contagious rage — it’s no surprise Ebrahimi took home the Best Actress Award when the film premiered at Cannes. Abbasi’s film is no easy watch, but it is a powerful entry in this subgenre that succeeds by making risky choices lesser works might have mismanaged.

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Holy Spider is currently playing in limited theatrical release and becomes available on digital in February. The film is 117 minutes long and is not currently rated.