Eva narrowly escaped being murdered during a recent terrifying home invasion in Mexico City. So she and her husband decide to relocate to Los Angeles where she can recuperate. But when her husband has to travel for business, she's left alone in an unfamiliar place and suffering from paranoia. She's consoled by the smart home security system, but the technology is difficult to master and she starts to wonder if it will actually keep her safe. Eva tries to remain calm, telling herself that she'll only be alone a few days before her husband returns. But soon her nightmares catch up with her, and the smart home technology takes note. The hostile security system begins to take over her life, analyzing her terror and stoking her fears until she reaches the breaking point, where her nightmares and hallucinations blur the lines between reality and imagination, and Eva has to fight for her survival.