The Tucker family can be called happy without a shadow of a doubt. Sarah looks after the house, gossips with her friends and grows vegetables in the garden, while her husband Kenny, an English teacher and part-time football coach, enjoys playing cards with friends. Together with their daughter Natalie, they live in a small American city, surrounded by friendly neighbors. The idyll of provincial life collapses when one night an unfamiliar girl appears on their porch, and the cozy town gradually begins to succumb to the onslaught of ever-increasing paranoia.