There is much about Rose Glass’ “Saint Maud” that’s horrifying and unimaginable, so let’s begin with its most poignant, relatable moment: the title character sitting in a bar, alone, just trying to be a person. She nurses a beer and glances around the room; she tries to make connections, trading flirty looks with a handsome young guy, trying to laugh along with a table of contemporaries nearby. None of it takes. Surrounded by people, she feels crushingly alone, and the more she is aware of it, the more she spirals. 

Maud (the magnificent Morfydd Clark) lives in a tiny, depressing room between her gigs as a live-in nurse. She prays, a lot, her “Dear God” voice-overs functioning in Glass’ script like Travis Bickle’s diaries; “You must have saved me for something greater than this,” she prays. “Not that I’m complaining or anything. Amen.” She lives what she believes to be a life of faith and service, though her words are troubling. When she gives her spare change to a beggar, she tells him, “May God bless you, and never waste your pain.”

There’s a sense, from the beginning – discounting the haunting but unexplained prologue – that something is a little bit off with Maud. There are scratches and marks on her body, and she seems visited by visions, or hallucinations, or something. We wait, with patience but increasing anxiety, for Glass to unpeel this onion; she reveals bits and pieces about Maud’s past with agonizing frugality; she runs into an old friend, for example, who calls her by a completely different name, and asks questions like “So you’re still nursing?” and “And they know what happened?” 

“Saint Maud” is Rose Glass’ first feature, and it’s an astonishing debut – the narrative force of her cuts and compositions is overwhelming, and she has a real gift for putting us into her protagonist’s head, via isolated sounds, industrial music, upsetting visuals. (The sound design, which is proving one of the most essential elements of cinematic dramatization of mental illness, is especially, exquisitely unsettling.) 

And Maud’s head is not a pleasant place to be. The genuine, palpable dread begins as a simmer and comes to a boil throughout the picture’s efficient 84-minute running time, particularly once Maud goes to work for Amanda (Jennifer Ehle, excellent) as a “dancer, choreographer, minor celebrity” sick with cancer. She’s a handful – the outgoing nurse describes her in, well, more colorful language – and a visitor describes her as living in “Norma Desmond territory.” But Maud sees her work as vital: “I have a responsibility to look after her. This is life and death.”

As such, she attempts to share her faith – a “recent conversion” – with Amanda, who is both amused and touched by her sincerity. She should be worried; Maud feels vibrations in the house, a spirit swirling through it, and one of Glass’ wisest calls is the degree to which she embeds Maud’s visions. She lets us see what Maud sees, and experience the world as she experiences it, and then reveals what’s real. Maybe.

Religious faith is too often an easy punch line in cinema, a snickering shortcut to indicate intellectual inferiority or just plain kookiness. But Glass takes Maud’s faith seriously, challenging herself to dramatize the ways in which this woman attempts to navigate a grim world with her spirituality intact. At two key moments, she subjects herself to makeshift self-flagellation, and this viewer couldn’t help but think of Harvey Keitel’s Charlie burning himself on the church candles in Martin Scorsese’s “Mean Streets”; he, too, is a filmmaker who shines all of his work through the prism of his religious upbringing, and grapples with the contradictions therein. “Never waste your pain,” Maud says again. And she means it.

As Maud descends into madness and fervor, the camerawork gets wilder, the music gets darker, and the close-ups get closer (particularly as Maud goes to work on a grotesque scab – peeling it away, both literally and figuratively). As she “prepares herself” for what she knows she must do, Glass seems to not only court “Taxi Driver” comparisons but welcome them. (There’s also an echo or two of one of that film’s most effective successors, “Ms. 45.”) She is recognizing the lurid signifiers of those films but drawing upon them for more than mere quotation (unlike one recent film that shall go unnamed). 

And in the picture’s stunning, shocking, but inevitable concluding passages, she ends up with something closer to “The Rapture,” another movie that asks real, hard, pressing questions about what it is to have and keep faith – undying, unquestioning faith – in the modern world. This is a stunning piece of work and a triumphant fanfare for the arrival of a remarkable new talent. [A]

“Saint Maud” is now open in U.K. theaters. A U.S. release has been delayed with no new date given.