Grace Thompson orchestrates neighborhood watch meetings from her impeccable home while maintaining detailed files on every family in her upscale subdivision. When a new couple moves in across the street, she recognizes the wife as someone from her past – a woman who should be dead. As Grace obsessively monitors the couple, her husband begins to notice holes in her stories about their own past, including inconsistencies about where they lived before and how they met. Their teenage son starts receiving anonymous emails revealing family secrets that only Grace could know. As the neighborhood's perfect facade crumbles, revealing a web of surveillance, blackmail, and hidden identities, Grace must prevent her carefully constructed life from imploding while keeping her family from discovering the truth about who she really is and the real purpose of her neighborhood watch program.