Jill Tyrell is a narcissistic sociopath who manages a beauty parlour alongside her moronic, asthmatic assistant Linda. When Jill learns that her husband has cancer, she uses this fact to manipulate new neighbour Cathy Cole, a wheelchair user with multiple sclerosis whose husband Don, a womanising doctor, Jill has become obsessed with.
Jill is picking up the pieces of her life after the murders at the end of the last series. She has managed to frame ex-boyfriend Glen for them.
Jill and Linda drive down to Cornwall as Jill goes in search of Cath and Don. On the way, Jill runs over a black woman and discovers that she was going to a job interview at The Trees, the therapy centre where Cath and Don are. Jill decides to take her place at the interview, despite the obvious difference in appearance.
Jill arranges an encounter with Don's girlfriend in an attempt to discourage her, while Cath pursues a relationship with her therapist.
Jill is still pursuing Don, even after finding out that Cathy is pregnant with Don's child, but her attempt to seduce Don is unsuccessful, so she seduces his 12-year-old son instead.
Jill decides that the only way left to infiltrate herself into the Cole household is to emulate Cath's pregnancy, and announces that 12-year-old Bruce is the father. Don responds by going into a persistent state of drunkenness.
Jill's lies are finally catching up with her. The man she framed for her husband's murder, Glen Bulb, escapes from the mental hospital. And Cath is becoming suspicious of Jill's "pregnancy", which is now entering its 11th month.
