Claire Foy ditches the Queen’s cut-class accent to play a paranoid American businesswoman.

She winds up involuntarily committed to a psychiatric institution after seeking help for the stress of coping with a persistent stalker.

Director Steven Soderbergh shot this psychological suspense thriller entirely on iPhones, which gives the action a scuzzy look that’s perfect for a down-and-dirty B-movie tale that will really give you the creeps. 

And Foy is excellent – this really is a long way from The Crown.