On the lush green lawns of London's Hampstead Heath Park, a variety of couples commune and sort through their assorted romantic dilemmas. Brian (Douglas Hodge) asks his partner, Billy (Ewan McGregor), to cease his constant carousing. Gerry (Hugh Bonneville) and Julia (Gina McKee) slog through what appears to be a very bad blind date. Meanwhile, Iris (Eileen Atkins) gets a blast from the past when she encounters a man she had a fling with 50 years earlier.