From the moment we meet luxury nursing home patient Douglas (Bruce McKenzie), we sense something is up. The gleam of complicity in his sky blue eyes; his thin gold chain and locks of chest hair sticking out of his medical pajamas; his accent low and measured: is it the voice of a former player who knows his mind is fading and is playing smart to save face? Or do you have perfect control of your faculties? In Georgia Bernstein’s gratifyingly perverse debut, “Night Nurse,” this ambiguity disrupts the usual dynamic between patient and caregiver, especially since Douglas’s doe-eyed new nurse, Elemi (Cemre Paksoy), seems especially vulnerable to being controlled.

An erotic thriller with the glassy-eyed unease of a Peter Strickland joint, and with the kind of slippery sexual sensitivity you might find in a Catherine Breillat tease, “Night Nurse” premiered in Sundance’s experimental NEXT section last January, and is now opening in limited theaters across the United States. a nice crime story.

In any case, the scheme that shapes the film’s stakes is introduced early on, in a sensual opening credits scene where the camera glides over curly telephone wires and grabs hands in close-up. Over these images, two voices languidly recite what seems like a role-playing game script, in which a desperate girl asks her grandfather for money. Later, we discover that this dialogue is a version of a game (albeit with real consequences) that Douglas plays with his nurses.

On the first night of Elemi’s shift, her patient corners her and shoves a phone in her face, demanding she play a hapless granddaughter begging her dad for money to make a deal; At the end of the call, Douglas takes over as his supposed lawyer. It’s not immediately clear whether this scam has any teeth or is simply an act, but soon the full extent of Douglas’s scam (which also involves his nurse Mona, coyly played by Eléonore Hendricks) comes to the attention of the care center’s leaders. This includes the steely Doctor Mann (Mimi Rogers), who may or may not have secrets of her own. There’s no (let’s say, conventional) sex here, but nasty mind games and rough, breathless encounters generate a satisfying amount of heat.

Played bravely by newcomer Paksoy, the restless Elemi immerses herself too willingly in her role, fueling the film’s spicy propositions about the dark side of devotion and the potentially strange desires that run, unsuspected, through dynamics of care and dependence. Bernstein was partly inspired by a true story involving his grandmother, who was almost the victim of a money transfer scam by someone posing as Bernstein’s brother, but the script only gestures to this exploitation in the real world, ultimately using it as a launching point for an erotic fantasy riddled with taboos.

Bernstein unfolds his mischievous intrigue in the Chicago suburbs where his grandmother lived, but the sterile, dimly lit places (swimming pools, carpeted living rooms, motel rooms) evoke a state of limbo more than any real place. Cinematographer Lidia Nikonova’s waxy images work alongside the cast’s slightly vacant acting styles to reinforce this trance, creating a confusing mood that echoes Elemi’s loss of control; his gradual surrender to Douglas’s newly unleashed impulses.

This brings us to the biggest (and perhaps most frustrating) mystery of the film: who is Elemi who falls so deeply under his patient’s spell? This ambiguity doesn’t seem entirely intentional, but at least Paksoy’s performance makes his character’s unraveling feel nervously and thrillingly palpable. And as the film moves toward its haunting finale, Bernstein pulls one last trick that reveals his triumphantly sick sense of humor: “Night Nurse” is also a romance with a black, bleeding heart.