Inspired by true events, Hampstead tells the story of American widow Emily Walters (Diane Keaton) who, having grown bored of her day-to-day life, sets out to find some more excitement. One day when exploring the gorgeous area surrounding her home in Hampstead Village she meets Donald Horner (Brendan Gleeson), a man who lives off-grid in his own private paradise on the Heath and the two strike up an unexpected romance. However, when unscrupulous property developers threaten to uproot Donald, destroy his home and build luxury flats in its place, Emily is determined to fight back to defend the Heath as well as the man she loves.