The award for least fearsomely titled horror movie surely goes to Personal Shopper.

Oh my God, I can't look. She's going to pay FULL PRICE!

But the movie is actually a ghost story, starring Kristen Stewart as Maureen, a young woman living in Paris, where her twin brother has just died, leaving behind -- so she believes -- the residue of his lingering soul.

Brother Lewis was a medium, which in the context of the movie's title might suggest someone who is not quite a large. In fact, he was the sort of medium who could commune with the souls of the departed, and had promised his sister that upon death he would find a way to make contact.

So she wanders his large, empty house looking and listening for signs. Things go bump in the night. Faucets turn on. Scratches appear in the paint. And finally spectral shapes form the air, and they are quite lovely until, as Maureen puts it, one of them "vomits ectoplasm."

It's not Lewis, she deduces, and her search goes on, augmented by Maureen's realization that she possesses her brother's gift for tapping into other dimensions, suggested by her casual costuming -- Converse sneakers, jeans, polo shirts. It's as if she's wearing her brother's clothes.

Her connection to the spirit world, however, does not help with her day job -- fetching clothes and jewelry for a famous-for-being-famous female celebrity, who sends Maureen bouncing back and forth between London and Paris, borrowing baubles from Cartier and clothes from famous designers.

Director Olivier Assayas has mapped out potentially interesting contrasts here -- two worlds colliding, the spiritual and the material. It's a good idea, but not much seems to arise from the way these two realms come into conflict. That's also true of the conclusion, when the movie's coy ambiguity seems to dissolve into a wishy-washy shrug. (The movie's enigmatic tone and approach are similar to the previous Stewart/Assayas collaboration, The Clouds of Sils Maria).

This puts a lot on the shoulders of Stewart, never the most demonstrative of performers. Here, she is bound by a role that's confining by definition. Maureen, like her brother, has a heart condition, and is under strict orders to avoid emotional extremes. Stewart takes that prescription and runs with it.

Assayas, in addition, does her no favors with a subplot that has her playing scenes opposite her iPhone. Seriously. In a scene that goes on for half an hour, she gets pinging texts from Unknown. Is it an unknown person, or is it the unknown?

The answer may leave you with buyer's remorse.