Ireland, 1970s. Eager to leave his dark past behind, Finbar Murphy (Liam Neeson) leads a quiet life in the remote coastal town of Glencolmcille, far from the political violence that grips the rest of the country. But when a menacing crew of terrorists arrive, led by a ruthless woman named Doirean (Kerry Condon), Finbar is drawn into an increasingly vicious game of cat and mouse, forcing him to choose between exposing his secret identity or defending his friends and neighbors.