On an island off the coast of New England in the summer of 1965, two twelve-year-olds (Kara Hayward, Jared Gilman) who fall in love, make a secret pact and run away together into the wilderness. As a local search party led by the Sheriff (Bruce Willis) and the girl's parents (Bill Murray, Frances McDormand) try to hunt them down, a violent storm is brewing off-shore – and the peaceful island community is turned upside down in more ways than anyone can handle.