Unsane review - Claire Foy in bonkers horror satire

Steven Soderbergh has always been capable of a big Hollywood moment – Magic Mike, Oceans etc. But much of his filmography consists of curious sideways glances. He’s particularly drawn to the shifting distribution of power between the genders. From sex, lies and videotape to Haywire, by way of Erin Brockovich and Out of Sight, he has rifled through the genres to find fresh and intriguing stories about men and women. It comes up again in Unsane, a sort of horror comedy satire that makes great use of Claire Foy’s vertical rise to bankability. It also, for the record, features a fun cameo from Soderbergh regular Matt Damon as an adviser of domestic security.

Foy plays Sawyer Valentini, whose very name suggests a split personality. She’s a single young woman who has moved from Boston to Pennsylvania to take up an office job and, seemingly, escape her nagging, needy mother. The new job is no panacea. The clients at the end of the phone test her patience and her boss is soon hitting on her. But deeper anxieties assail her. She hooks up with a hot guy on a dating app and, having promised him sex, thrusts him away in disgust.

Distraught, one lunchbreak she drives over to a hospital to talk to someone about her history of being stalked which, she concedes, has brought on bouts of suicidal ideation. Barely is the session over before she has unwittingly signed a form consenting to her forced hospitalisation. When she objects, agggressively, the period of what feels like incarceration is extended from 24 hours to seven days. The creepily long and empty corridors and impassive white-coated staff inevitably evoke One Flew Over the Cuckoo’s Nest.

Sawyer's fellow patients would all seem to be as psychotic as Violet (Juno Temple, pictured above, very different from her wide-eyed turn in Woody Allen’s Wonder Wheel), who occupies the next-door bed. But she forms a bond with Nate (Jay Pharaoh), who counsels her to accept that everyone in Highland Creek Behavioral Center is being milked for their insurance money. When that runs out, they will be released. This would be reassuring if Sawyer hadn’t spotted her stalker from Boston wearing a nurse’s uniform and handing out the daily cups of medication. The nurse (Joshua Leonard, pictured below) insists he’s called George, not David Strine as she claims.

The script by Jonathan Bernstein and James Greer has no great truck with plausibility. How David/George could have landed this job and fetched up in Sawyer's life is not examined. The plot flirts with the idea that Strine is a figment of her imagination: is she hallucinating a beard, glasses and a lovelorn gaze onto every threatening male? But gradually scales fall from eyes as Sawyer is slipped her mind-bending medication, offering Soderbergh a chance to work up some woozy visuals (incredibly, he shot the whole thing on an iPhone). Then, after Sawyer summons her mother (Amy Irving) to rescue her, more disturbing things start to happen.

This is a robust breakaway for Foy, who has spent two years rei(g)ning it in as Her Majesty. She’s blonde, brittle and not altogether likeable here, and yet connoisseurs of her Queen Elizabeth will recognise her face’s powerful facility for exuding hurt and offence. She gets plenty of practice at that before the latter part of the film moves into new realms and calls for different colours. Unsane stops being a Kafkaesque satire of Big Pharma and the medical insurance racket, and mutates into a horror riff on the psychosis of delusional male sexuality. Perhaps insurers and stalkers are even cut from the same cloth. It’s all a bit bonkers, though nothing if not timely.

• Read more TV reviews on theartsdesk

@JasperRees

Overleaf: watch the trailer to Unsane