Some films are deliberately challenging, some meanings are proposed to be elusive; Olivier Assayas should offer a cash prize for anyone who can confidently synopsise his supernatural thriller Personal Shopper. Twilight fans with a crush on Kristen Stewart will get more than they bargain for in this strange story set in the world of high fashion. Stewart plays an intern in mourning for her twin, who has recently died. After an ectoplasm manifestation which looks straight out of Ghostbusters, Stewart is menaced an unknown assailant by phone, via a series of cryptic messages. Do ghosts use social media? Or it the man who attack her boss after her? A series of tense scenes further the story without ever explaining what’s happening, and scenes which feature an invisible ghost boggle the brain. Stewart is absolutely brilliant in this role, mixing movie-star looks like a fragile vulnerable character that generates huge involvement. If the climax doesn’t make sense, the coda further muddies the waters; Personal Shopping is a great, original film, just don’t ask what it means.