Four friends find their lives interwined when they are all touched by infidelity.
Siobhan tells Jessica what happened between herself and Dominic after becoming overcome with guilt. When Richard asks Trudi out to dinner not everything goes to plan. Hari and Siobhan try to find out what she is finding it so hard to get pregnant.
Katie tries to fight her feelings towards Sam. Trudi finds out who is behind the calls she has been receiving.
Richard manages to upset Trudi. When Siobhan doesn't make it to the clinic, Hari is none too pleased.
Siobhan helps Dominic to gain a promotion. Siobhan finds herself under pressure to admit the truth to Hari. Trudi is determined to win Richard back at any cost.
Trudi discovers a shocking secret; Siobhan has to make a difficult decision; and Katie goes to a hearing concerning John's death.
The girls get together to celebrate Jessica's impeding marriage to a rich playboy. Siobhan is keeping a secret. Katie manges to catch the eye of a colleague.
One of her former conquests ends up being one of Siobhan's new clients. She becomes worried that her secret night time life is going to be exposed. Richard's continued spending makes Trudi suspicious.
Trudi is determined to discover the truth after confronting Richard. When Hari refuses to forgive her for her affair with Dominic, Siobhan ends up in Tom's bed again.
Jessica is reminded of what happened after she got drunk but still makes up with Mark. An unexpected visitor upsets their happiness. Trudi gives Richard a chance to explain what has been going on. Katie is surprised by Jack. Siobhan tries to sort out her marriage problems.
Jessica and Mark attempt to be exclusive with one another. Trudi turns to Lucas for comfort. Katie thinks about leaving England with Dan for a new life in Australia.
Katie is single again now that her affair has been found out by Dan, but Jack is still keeping the truth from Megan. Trudi finds it hard to forget Lucas. Siobhan finds it hard to escape Tom's control. Mark asks Jessica to take him back after he discovers her secret.
A couple of years have passed and the once impenetrable bond between best friends Katie, Trudi, Jessica and Siobhan has been shattered.
Katie finds herself taking a trip down memory lane when she pays a visit to the house when her interfering mother, Vivienne, announces that she's planning to sell the property. Katie ends up uncovering a secret which could ruin her childhood memories. Trudi is still finding it hard to to juggle her successful cake-making business and home life. Jessica looks forward to starting her IVF treatment despite the cost.
Trudi feels guilty after having evening with Chris and ends up telling Katie as she she wonders whether she should tell Richard what happened. Siobhan goes out on a date with Jeff after she realises that Dominic has moved on with his life. Dominic feels jealous and he ends up making a pass at Siobhan, but he later realises that it would be better is they just distance one another further. Jessica and Mark's money problems continue to drive them apart. When Katie realises that she and Richard are becoming too close she makes it clear that she wants nothing more to do with him.
Trudi, Jessica, Katie and Siobhan find themselves united in their grief following the death of a somebody they were all close to. Grief turns to anger at the funeral though as there are many unanswered questions. The friends don't speak for a couple of months but a heartbreaking announcement ends up bringing them back together. Siobhan becomes confused about her feelings for her new boyfriend, Jeff. Trudi is in a panic after Amy disappears.