NEONA woman (Léa Seydoux) wanders through a street market in Paris. We see her through the lens of a camera, one operated by David (Niels Schneider), a photographer who spends much of his life peering at the world through a lens. He’s been strangely captivated by this woman, but as she walks briskly through the streets, he loses her. However, later that night at some anonymous club, he sees her again in the crowd. This time, she sees him and locks eyes. She walks purposefully through a door to an empty stairwell, and David gets the hint and follows her. Silently, they undress and start having sex. But as the woman reaches completion, something strange happens. She screams, seizes, and passes out; shortly after, David does the same.A few hours later, the woman wakes up alone. Disoriented, she gets into a cab back to her apartment — or wait, David’s apartment? Stumbling inside, she catches a glimpse of herself in the mirror and pukes. Shocked, she stares at her reflection, and it becomes immediately apparent that this is not the mysterious woman, but David trapped in her body.The Unknown, directed by Anatomy of a Fall co-writer Arthur Harari, is a curious little film. It’s an unnerving body-swap drama that dabbles in psychosexual thrills and weird cosmic mysteries, but is less concerned with those than it is with the inherent loneliness of its premise. The mysterious entity that swaps bodies through sexual intercourse leaves a trail of displaced people in its wake; stuck in the bodies of strangers and isolated from their former lives and loved ones, many of these victims drift off into the fringes of society, going missing or simply disappearing.David already lived a bit of a lonely existence, but trapped in this woman’s body, he isolates himself even more, ignoring the phone calls from his concerned friend and his mom, who always thought of him as “fragile.” But he has a few lifelines: the photos of the woman he had taken previously, and a note that he finds in her coat pocket. Using these scant clues, he traces the woman’s steps back to a shabby apartment that looked like it had been abandoned for weeks. It belonged to a woman named Eva, a struggling actress and waitress, he learns. Packing up a few of her clothes and belongings, he leaves a note on her door, hoping that Eva will return to find her body. But when he learns from a friend that he’s been spotted sleeping on the streets, David discovers that the person now inhabiting his body is not Eva, but a college girl named Malia, who encountered the entity in David’s body at a party. David takes Malia in, and the two of them attempt to track the entity down through its various victims, but to no avail. Slowly, Malia grows more despondent, while David stoically fights back the looming sense of hopelessness.The Unknown is very much a two-hander between Seydoux and Schneider, who are scarily convincing as their body-swapped characters. Seydoux embodies that forlorn, slightly creepy personality of David in her hunched shoulders and tight expressions, while Schneider practically crumples into a weepy ball every scene as the despairing young Malia. Their tense dynamic carries The Unknown through its surreal twists and turns, which Harari, who co-writes the script with Lucas Harari and Vincent Poymiro, shoots with a very no-frills approach.But the bare-bones direction and style of The Unknown lends to the inherent loneliness of its characters and its stories. It meanders, it wanders, and but never offers satisfying or easy answers. “The Unknown” the title refers to, may very well be the mysterious body-swapping entity, but it also may be ourselves, once separated from our bodies and lives. Harari wisely doesn’t linger too long on these questions, at risk of stretching out an already thin premise, but lets the audience just sit with them as this strange tale unfolds. The Unknown may not do anything novel or revolutionary with its body-swap premise, but it certainly makes one think about the terrifying consequences of what would happen if one were to lose their body and never regain it or their life as they knew it.The Unknown screened October 2 at the New York Film Festival. It does not yet have a release date.