Dave Davis in “The Vigil.” Courtesy of TIFF

Horror films often offer catharsis, but rarely are they also as deeply sorrowful as Keith Thomas’ “The Vigil,” a horror film based in Jewish faith and culture. Dave Davis stars as Yakov, a young man in Brooklyn struggling to establish a secular life, having left the Orthodox Jewish community after a traumatic experience. One night, leaving a support group meeting, he encounters someone from his old life, Reb Shulem (Menashe Lustig), who offers him a job spending the night as a shomer, a person who serves as a protective watchman over a dead body before it is taken to be buried.

The first red flag is the urgency of the request: The first shomer left unexpectedly in fear. But Yakov is in need of the cash and has done this before. If the dead man’s wife, Mrs. Litvak (Lynn Cohen), is behaving a bit strangely (Shulem explains she has Alzheimer’s and her husband was a recluse), it’s only five hours, and he can stick it out for the 400 bucks.

Initially, Yakov chalks up all the spooky occurrences in the home, including his nightmares, the bumps in the night, the twitching shroud, a figure looming in the dark, to his faltering mental health, placing a call to his psychiatrist. But he can’t ignore the strange technological invasions within his newly acquired iPhone, or Mrs. Litvak’s troubling behavior and warnings. She describes to Yakov the mental torture that she attributes to an ancient demon, the Mazzik, that plagued her husband and drove their children away. “These memories,” she says, “they bite, and the biting never stops.”

“The Vigil” is Thomas’ directorial debut, and the filmmaking is efficiently creepy, if a bit leading. The camera moves and frames and pointedly directs your attention to every small detail you, as a viewer, should focus on, lingering so long you feel you’re practically willing the sheet to move, or the shadow to emerge from the darkness. It’s an effective way of placing us in Yakov’s position, questioning whether these things are actually happening or if our mind is playing tricks.

Michael Yezerski’s score is equally forceful, the ominous tones practically screaming at us that “something bad is about to happen here.” The score is a bit more effective when it swirls into more abstract electronic compositions, but Thomas’ approach to tone is unabashedly horrific, embracing the not-so-subtle elements of horror style that guide and shape our expectations and emotions. Thomas utilizes the genre as a tool to tell this story that uses Jewish lore and demonology to talk about memory, catharsis and trauma, and Davis’ incredible performance brings a deeply sad and rueful element to the film.

“The Vigil” embraces Jewish culture not just in its settings and religious symbology, but in the way that memory and the processing of intergenerational trauma is a crucial part of Jewish existence, especially after the Holocaust, while reckoning with anti-Semitism and hate crimes to this day. It articulates that collective catharsis can alleviate those biting memories and traumas of the past in the present, allaying grief through personal atonement and forgiveness. Because those demons can be scary, but scarier still are our own regrets that go unrectified.