Certificate: 15

Running Time: 98 mins

Star Rating: 3/5

SEEING is deceiving in Steven Soderbergh's hallucinogenic mind trip for a traumatised data analyst, who sees the menacing face of a stalker everywhere she turns. Scripted by Johan Bernstein and James Greer, Unsane is shot entirely on a smartphone and generates sparks of claustrophobia from the restricted screen framing and occasional blurring of images as characters race around dimly lit corridors. Visuals are intentionally murky, reflecting the gloom that descends upon the stricken heroine. Shaky handheld camerawork has a verite, improvised quality akin to a fly-on-the-wall documentary rather than a studio-financed psychological thriller.

Stockport-born actress Claire Foy is Sawyer Valentini, who has moved from Boston to Pennsylvania to escape the barrage of text messages of a mentally unstable admirer called David Strine (Joshua Leonard). Human interaction is limited to clipped conversations with work colleagues, anonymous hook-ups in bars and reassuring telephone calls to her concerned mother (Amy Irving). Always looking over her shoulder, Sawyer searches online for support groups for victims of stalking. She is directed to Highland Creek Behavioural Centre, where trained staff will apparently diagnose the best course of action.

Unsane sacrifices deep and satisfying character development to explore the freedom that smartphone technology grants an Oscar-winning filmmaker, who can now get uncomfortably close to his protagonists in confined spaces - both real and imagined.