“Personal Shopper,” the hypnotic and quietly unsettling new film from French director Olivier Assayas, asks us to consider the concept of ghosts in more of a subjective sense rather than an objective one. Ghosts aren’t empirical beings that wander around the land of the living on their own but entities born from our own emotional state of mind. That’s why some people claim to experience ghostly presences while others don’t. They’re projections of our fears and anxieties, our guilt and sorrows, our regrets and even our curiosity. Ghosts can be a source of terror and torment but they can also be a source of self-help. Someone who goes to a Medium or Psychic to make contact with a deceased loved one does so for his or her own well-being, for a sense of emotional closure. Perhaps that person feels guilty for their loved ones death or they just haven’t accepted that they’re gone.

Maureen (Kristen Stewart), the protagonist of “Personal Shopper” hasn’t gotten over the death of her twin brother Lewis. So she waits patiently, hoping to make contact with him. She currently lives in Paris (where he lived) and works as a personal shopper for a fashion model to pay the bills, a job she hates but does well. Maureen’s been there for a little over three months and little progress has been made. She’s beginning to grow restless and agitated, struggling to keep her mental composure. It’s at this point that she starts conversing with a mysterious ghost via text message as she travels around Europe on various shopping excursions.

The ghost is a peculiar one to say the least. Sometimes it teases and toys with Maureen, other times it acts like a psychiatrist, asking her tough questions and forcing her to confront repressed feelings. And sometimes it can be erratic and intimidating, snapping at her like an unstable stalker. The ghost is a manifestation of her distraught, unbalanced state of mind that finds her at the right time. In her interactions with this entity, Maureen is able work through her problems; she comes face to face with her deep seeded anxieties and insecurities, not just in regards to her dead brother but in regards to her own sense of self purpose and uncertain future. Right now she’s on a clear mission, (to make contact with her brother) a mission that guides her and gives her purpose. Though once she makes contact, what then? What’s will she do next? What will her purpose be? And when she does make contact with Lewis will that really bring her closure? These questions (and others) haunt Maureen at all times.

The tense, sometimes humorous, sometimes tender text message conversations are among the best scenes in the entire film. Watching Maureen’s progression (from initially resisting the ghost’s digital beckons, to slowly giving into its games and interrogations and ultimately opening herself up emotionally) is endlessly absorbing. “Personal Shopper” is a poignant and thoughtful portrait of personal grief and acceptance with the exhilarating slow burn pacing and structuring of a psychological thriller. Assayas lets the plot unfold with a subtle, unassuming tension and doesn’t spoon-feed the audience. Details concerning character and background are revealed organically, often times through casual conversation and some things are even left unstated.

Though “Personal Shopper” wouldn’t work nearly as well without Stewart’s understatedly magnetic performance. Her natural, low-key onscreen presence is both comforting and hypnotic — she’s in nearly every frame of “Personal Shopper” and you can’t take your eyes off her. As the resilient but damaged Maureen, Stewart exudes an unshakable confidence and put-together-ness that allows her to function in her life as a personal shopper and also masks an internal emotional fragility threatening to overtake her. The brief moments where she allows herself to breakdown and succumb to her overwhelming grief are heart wrenching. In her interactions with the other characters she can be calmly snarky and quietly compassionate. Through her nuanced work here, Stewart continues to prove she’s one of the best working actors.

“Personal Shopper” stumbles a bit when it deals with a murder mystery subplot.  It’s fun to watch in the moment  (Assayas treats it with the same tautness as the rest of the picture) but it ultimately fizzles out, making you wonder why it was there in the first place. Then again, I could be wrong about that, in fact I could be wrong about my overall summation of the film — in regards to how it views ghosts/spirituality. Assayas wisely doesn’t make any definitive statements when it comes to the events and ideas in the picture, meaning you can interpret it any number of ways. “Personal Shopper” is a deceptively complex, intense and emotionally rewarding experience.