Kristen Stewart glides between two different types of movies in “Personal Shopper.” Neither works on its own, exactly, and the two types almost seem to come from different scripts.

But blend them together with Stewart’s somber underplaying, and you’ve got something intriguing, maybe even haunting.

We are in Paris, where a young American named Maureen, played by Stewart, is grieving the recent death of her twin brother. The siblings shared a heart condition (Maureen’s doctor tells her to avoid excitement and emotion) as well as a gift for sensing the spirit world.

At least, Maureen’s brother thought he was a medium. She isn’t so sure, although she hangs around his big empty house, trying to communicate with his ghost.

Meanwhile, she’s working as a personal shopper for a chic celebrity. This storyline leads into a genuinely suspenseful thread about Maureen being stalked by someone via text message, a threat that has a violent conclusion.

Writer-director Olivier Assayas, who previously worked with Stewart in “Clouds of Sils Maria,” applies his usual open-ended approach to filmmaking here. There are scenes that feel curious or unnecessary, as though they were whims of the moment.

The suspenseful part of the film goes like clockwork, however. You almost get the feeling Assayas wanted to challenge himself to make a Hitchcock picture in the age of the smartphone. On that score, he completely succeeds.

While I was watching “Personal Shopper,” I wasn’t always sure about its apparent randomness. Then, in a final sequence set in a completely different location, the entire thing snaps into focus.

At the center of it all — quite literally — is Kristen Stewart, whose inward-directed presence sets the solemn tone. It’s amazing how often Stewart is alone on screen in this film, moping through empty rooms or slipping into her employer’s designer outfits as though trying on a different personality.

This odd little film reminded me of Val Lewton’s 1943 ghost tale “The Seventh Victim,” which is also about a young woman searching for a lost sibling. Both are mood pieces, not horror movies, and they come to a similar conclusion: Instead of worrying about ghosts or other supernatural fantasies, we might all be better off dealing with earthly concerns and our own mysterious selves.

“Personal Shopper” (3 1/2 stars)

Kristen Stewart brings her somber underplaying to this study of a young woman in Paris coming to terms with her twin brother’s death by trying to speak with his ghost. Director Olivier Assayas combines this with a suspenseful thread about a stalker, and the results are unexpectedly haunting.

Rating: R, for nudity, language, violence

Showing: SIFF Uptown, Sundance Cinemas