A stressed-out stalking victim (Claire Foy) unwittingly commits herself to an asylum for observation—then begins raving that her stalker is one of the institution’s male nurses (Joshua Leonard). Foy harrowingly sheds her royal image as Elizabeth II in TV’s The Crown, and director Steven Soderbergh, shooting the whole film with digital iPhone cameras, gives the movie a jumpy, disorienting energy, looking somehow wide-angle and claustrophobic at the same time. That’s the good news. The bad news: Jonathan Bernstein and James Greer’s script is a low-schlock thriller, patently implausible and tipping off its “secrets” much too soon. It’s exhilarating to see Soderbergh, with nothing to prove, still willing to experiment, and Foy’s performance is riveting, but they’re essentially putting lipstick on a pig.