The marriage of Danny (Douglas Henshall) and Hannah (Catherine McCormack) spectacularly crashes during the reception when the bride's best friend tells the groom that the bride is having an affair with her husband! The shock wave of chaos that spreads out from this one event touches the lives of a diverse group of the thirtysomethings that inhabit the Camden Town area of London. Hannah immediately leaves the reception and gets drunk and ends up in bed with the unwashed artist Cameron (Dougray Scott) who is a friend of struggling singer Mary (Kathy Burke). Danny meanwhile moves on, opens his own tattoo parlour and eventually starts an affair with society dropout single-mother Sophie (Jennifer Ehle). This partner-swapping merry-go-round continues for two years until a semblance of normality asserts itself and Danny and Hannah decide to drop everything and embark on their long delayed honeymoon.