In the drama “Personal Shopper,” director Olivier Assayas reunites with Kristen Stewart to take us through one woman’s time spent grappling with life’s unanswerable questions. Is there an afterlife? Do our loved ones ever leave us? Can we truly move on? These questions haunt all of us. Deeply thought-provoking and hard to classify, this eccentrically told picture uses its titular profession to examine how even what we can’t or don’t see can leave their marks forever.

Maureen (played by Stewart) is the personal shopper and assistant to Kyra, a bratty celebrity with whom she rarely interacts. Recently, Maureen lost her twin brother, Lewis, who died at 27 from a congenital heart defect. But, Maureen, who shares the same health defect as him, is also a spiritual medium. In between errands, she stops by her childhood home outside Paris, anticipating Lewis will make contact with her from the other side as part of a pact the siblings once made. But, when Maureen starts receiving phone texts from “Unknown,” who may or may not be Lewis’ ghost, she must figure out the messenger’s identity and what they want, even as it becomes evident she hasn’t gotten over losing her brother.

If the “Twilight” franchise led you to question Stewart’s abilities as an actress, then “Personal Shopper” will make you immediately take back that negativity in humble apology. Limited in that blockbuster universe by weak characterization and a questionable plot, this art-house world demonstrates Stewart’s tremendous and underestimated capacity to create a vivid internal life for a character, when given material as intelligent as she is. In a film that mostly relies on simple dialogue to convey complexity, she successfully communicates Maureen’s difficult journey in grief processing, mostly alone and often non-verbally. The emotion iss in the eyes and body language, as Maureen spends most of the film in a state of desire for something more, be it finding closure with Lewis or secretly trying on Kyra’s wardrobe. Stewart’s trademark fluid androgyny is what ultimately makes her performance as Maureen so effective. In a film that’s not afraid to leave nagging questions unanswered and to march to the beat of an abstract plot, Stewart holds nothing back as a category-defying artist in an industry that often wants everything it touches to be in its own specific little box, particularly when it comes to gender expression.

The film seamlessly blends elements of psychological thrillers with those of ghost stories to create an unsettling melancholy that taps into our fascination with and fear of death. This is best exemplified in the scenes where Maureen is alone in her childhood home, waiting for a sign. Even without gross-outs or jump scares, these moments are still nerve-wracking. As it often is with the topic of mortality, we ache to know, but are simultaneously terrified enough of the possible answer to not want to know. One of the film’s most outstanding achievements is its ability to build tension through text messaging better than most slasher films put together. There’s no corny overly orchestral music, no exaggerated panicking. Just the click of an iPhone keyboard, the three periods typing to indicate progress from the other end, and the whoosh of a message received. In those sequences, “edge-of-your-seat” earns its name.

Like Maureen in the end, some viewers may feel incomplete when loose ends are left untied. But “Personal Shopper” realizes that that’s life. There are some things that we will never find out. And why worry, when you’ve got another day of this life to live?