The protagonist of Olivier Assayas’s new film Personal Shopper, Maureen, is somewhat of a wraith. Skinny, angular, and mostly silent, she visits high-end Parisian boutiques and picks out clothes for her demanding celebrity boss, never trying them on, zipping from one store to the next on a motorcycle. If she knows how impossibly cool her life seems from the outside, she doesn’t show it. Instead, Maureen (Kristen Stewart) seems intent on keeping the audience at arm’s length, even as we watch her go through a period of wrenching grief while simultaneously grappling with the supernatural.  

Because, you see, Maureen is no ghost but a medium, who in her downtime communes with the spirit world. She’s also haunted (perhaps literally) by the loss of her twin brother, who shared her powers and recently died of a congenital heart defect. If this all sounds confusing, then strap in, because Personal Shopper has plenty more surprises, some unsettling, others completely confounding. Assayas’s great new film is by turns sinister, jarringly mundane, and entirely inimitable, as it explores the peculiar sorrow of losing a loved one while avoiding the obvious routes such a tale would usually take.

It’s not quite a masterpiece like Assayas’s last movie, Clouds of Sils Maria (2015)—the director’s first collaboration with Stewart, in which she played a disaffected but insightful assistant to Juliette Binoche’s aging star actress Maria Enders. That film looked at mortality in a more abstract way, examining how our relationship to art changes as we get older. It also offered a portrait of a woman suspicious of both the coming waves of young talent in her industry and the limiting roles she’s forced to take as she gets older. There, Stewart was a supporting presence, a sort of droll conscience to Maria who nonetheless helped remind her of her advancing years.

In Personal Shopper, Stewart is still playing an assistant, but she’s the star, and she moves through the film with the same disconsolate detachment that she played so well in Clouds of Sils Maria. Maureen is looking for a sign from her brother, who assured her he’d try and contact her from beyond the grave if he died before her. She has plenty of otherworldly encounters, but none of them feels quite definitive. The metaphor is obvious, though no less powerful. Though Assayas presents all of Maureen’s freelance ghostbusting with a straight face, it’s evocative of any experience of loss, and the sense of confusion, fear, and emptiness that follows.

When she’s not shopping for her demanding boss, Maureen spends much of her time wandering around a supposedly haunted manse in the dark, in search of some sign of her brother’s spirit. It’s genuinely unnerving stuff and among the best creeping horror of the last year, though it quickly spins into wild, unexpected directions. Maureen encounters some ghosts of the traditional sort (this is not a film that’s trying to be ambiguous about the authenticity of her gifts), but she also starts receiving texts from an unknown number that seems to be following her wherever she goes and asks probing questions about her work and love life.

It’s a strange miasma of genres and modern anxieties. Maureen grapples with the pain of her brother’s death, the bump-in-the-night phantoms of the haunted house, and with being stalked and harassed via smartphone. Assayas commits long sections of the film to text-message conversations between Maureen and her unknown correspondent. Somehow it works, especially as the text messages begin to demand that she try on the clothes she buys for her boss (which she’s forbidden to do), as if this will cause her to inhabit her boss’s body.

Personal Shopper won’t work for everyone (it was booed at the Cannes Film Festival last year). But it will stick with you even if you don’t immediately know what to make of it, given that Assayas leaves the viewer with so many intriguing visual ideas and puzzling story twists to obsess over after seeing it. Stewart, who at this point has to be recognized as a major talent, brings the same brittle vulnerability she deployed so well in Clouds of Sils Maria and 2016’s Certain Women, vacillating between the cool self-confidence of her day job and the odd performativity of trying to talk to a ghost when standing alone in a room. Like so many, Maureen is searching for answers about human connection and the spiritual bonds of the universe—answers that feel frustratingly opaque, even when they’re given. At once poignant and chilling, Personal Shopper is a wonderful evocation of that maddening sensation.