All 16 episodes of the Bristol-set BBC drama focusing on the lives of four friends - Katie (Sarah Parish), Trudi (Sharon Small), Jessica (Shelley Conn) and Siobhan (Orla Brady) - who are drawn into a world of illicit and complex relationships. The 30-something friends met at university, but their lives have gone in very different directions: Katie is a doctor and has been having a relationship with one of her patients; her best friend Trudi is grieving for a husband lost in 9/11; bubbly bed-hopper Jessica remains ecstatically single; while lawyer Siobhan seems happily married. Now, the shadow of infidelity is about to cast all their lives into a dizzying maelstrom as Katie finally reveals her close-kept secret, Trudi embarks upon a series of disastrous dates, Siobhan discovers real passion and Jessica is forced to face up to her own emotions.