Mistresses - Katie is falling for Sam

29 January 2008 @ 9-10pm on BBC ONE

Despite Trudi's disapproval, Katie throws herself into an affair with Sam, in the drama following the lives of four women and their relationships. She's falling for him, but her joy at their relationship is tempered by her burdensome secret.

Trudi refuses to believe that Sally was Paul's mistress and demands proof. When Sally presents Trudi with a pair of Paul's cufflinks, she is dumbstruck. However, the girls dismiss it as the mark of a fraudster and tell her to steer clear.

Unaware of Trudi's personal crisis, Richard attempts to charm her back into the bedroom. However, she rejects his advances and their relationship begins to take a turn for the worse.

Having accepted his infertility, Hari arranges to see a specialist. Knowing she's already pregnant, and fearing discovery, Siobhan doesn't turn up for the appointment and Hari is furious. Siobhan comes to her senses when she realises she has no future with Dominic and she goes to the clinic, knowing her pregnancy will be revealed.

Elsewhere, after waking up hung-over and confused in Stella's flat, Jessica is feeling hugely unfulfilled. In an attempt to determine her sexuality, she arranges a threesome with her boss, Simon, and Stella but, after another disappointing night she consults with Katie who has a surprising diagnosis: she's in love.

Meanwhile, Katie is unable to carry on lying and finally confesses to Sam about her relationship with his father. Sam is furious and storms off, leaving Katie fraught, confused and alone.

Trudi is played by Sharon Small, Katie by Sarah Parish, Sam by Max Brown, Sally by Joanne McQuinn, Richard by Patrick Baladi, Hari by Raza Jaffrey, Siobhan by Orla Brady, Dominic by Adam Rayner, Stella by Isobel Middleton, Jessica by Shelley Conn and Simon by Adam Astill.