Unsane

The press notes for Steven Soderbergh's Unsane come with a pleasant advisory at the top, politely requesting that journalists don't reveal the "characters' secrets" in subsequent reviews. It's a noble intention - and one I fully endorse - but it's a shame that writers Jonathan Bernstein, James Greer and even Soderbergh himself appear not to have received the memo.

As it is, the filmmaking team seems determined to telegraph almost every ounce of surprise in the film, nudging the audience to know exactly what anyone's state of mind is at any given point and who we should be rooting for. That the biggest surprise of the film is not a plot point at all but the appearance of someone famous in a cameo role, speaks volumes. And, no I won't spoil it for you.

Despite all this, Unsane does have a certain retro charm, almost because of rather than in spite of its predictability, along with an enjoyably full-on central performance from Claire Foy. She plays the chewily named Sawyer Valentini, who after a spot of sinister initial sinister voice-over, we meet in what could easily be hastily snapped surveillance footage - an interesting conceit given that the film was shot on a trio of iPhones.

After a disastrous date leads to a disorienting panic attack, she heads off to see a shrink, revealing that things haven't been going too well for her since she acquired a stalker, who she can't shake from her mind despite moving cities. Before you can say, 'Do you have insurance?', she finds herself admitted for the week, itself only the first in a string of horrors that also include a belligerent young woman in a neighbouring bed (Juno Temple, doing her best with a role that could have been plucked straight from Shock Corridor and which is thinner than her bedsheet) and the discovery that, as far as Sawyer is concerned, her stalker (Joshua Leonard) is on the staff. There are some nice scenes with a more supportive fellow patient Nate (Jay Pharoah) but he also suffers from having too much about him revealed too soon.

The squared-off nature of the iPhone framing does give everything a claustrophobic feel, enhanced by the flat lighting and recurrent presence of blue in everything from the filter used in the film's opening minutes, to cardigans and a padded cell. Most disappointingly, while the narrative busies itself in cliched psychological horror territory, it side-steps much more interesting ideas that are floating around. The payment system that might see people incarcerated against their will for their cash is one of the most chilling aspects of the film and yet it is hardly explored, while the rest of the hospital's attending staff who could have provided much needed menacing ballast are purely one-note. Worth seeing for Foy but, as Soderbergh's experiments go, it lacks any memorable chemistry.