An American widow (Diane Keaton) finds unexpected love with a man (Brendan Gleeson) living wild on Hampstead Heath when they take on the developers who want to destroy his home.
Hampstead Village, London, is famous for its beautiful and much-loved Heath; a piece of quiet countryside in a vast metropolis.
Living on the edge of the Heath is American widow Emily Walters (Diane Keaton), who can't quite focus on the things that need attention since her husband’s death; like her crumbling old apartment, diminishing finances and even her son, Philip (James Norton).
Despite encouragement from her close friend Fiona (Lesley Manville), she doesn't want to admit that she's merely drifting through life. One day, while looking out across the Heath from her attic window, Emily spies a ramshackle hut, which appears to be inhabited by an unkempt man. After witnessing him being attacked by a group of professional thugs, she calls the police and watches through her binoculars as help arrives. The next day she ventures into the woods in search of him.
Donald Horner (Brendan Gleeson) has lived quietly and harmoniously on the edge of the Heath for 17 years but his lifestyle is under threat - his home is the target of property developers who’ve started using heavy-handed tactics to remove him. He is naturally suspicious of Emily and politely rebuffs her attention but despite his gruff exterior, there is something gentle and alluring about him. When Emily discovers that Fiona is leading a community initiative in support of the developers, she bravely steps up to take Donald's side in the escalating battle to save his peaceful Heath dwelling. Though Philip tries to persuade her to retire gracefully to the country, she is determined to defend the emotional and physical livelihood of this quiet and unusual man - a man who might just be the person to sweep her off her feet.
Inspired by a true story, Hampstead is a charming and funny life-affirming tale about how love can be found in the most unexpected places and proves once and for all that age is no barrier to second chances.