Romantic comedy drama centring around various couples discussing their romantic and erotic tribulations on a sunny afternoon on Hampstead Heath. Julia (Gina McKee) and Gerry (Hugh Bonneville) are on a blind date, but don't seem to be enjoying one another's company. Billy (Ewan McGregor) and Brian (Douglas Hodge) are a gay couple at a crossroads: Billy wants to settle down and adopt a child, but Brian doesn't believe this will curb his partner's chronic infidelity. Iris (Eileen Atkins) and Eddie (Benjamin Whitrow) were together many years ago, but aren't sure what to make of one another when they meet by chance in the park. Sara (Catherine Tate) and Pete (Adrian Lester) discover how much they care for one another just as they're on the verge of divorce. Jamie (Andrew Lincoln) finds he has some explaining to do when his wife Molly (Holly Aird) catches him eyeing up a pretty young woman (Eglantine Rembauville) who is inadvertently exposing her underwear. Ludo (Nick Sidi) and Anna (Sophie Okonedo) are a couple whose romance doesn't seem fated to live out the day. And Noel (Tom Hardy) is a lecherous sort who is looking for a woman as interested in sex as he is.