Jessica and her fiancé, Evan, have recently relocated from the city to their ideal house on a peaceful suburban street. Not long after settling in, Jessica discovers that their apparently amiable new neighbor, Simon, has been dishonest about something, and her suspicions refuse to fade. The situation becomes more perilous when Simon tricks her into entering his house and traps her in a hidden bunker, which he has carefully adorned to resemble the perfect 1950s setting.