Season 3, Episode 29: "Cruel to be kind" (original air date: November 20, 2002)

Nicky is growing tired of playing taxi driver to her new flatmate, Helen. More importantly, she is getting tired of Helen's slackness as a doctor. This comes to a head when Helen treats Gil's daughters, Gwyneth and Rosie, who both suffer from epilepsy. Their mother, Denise is very protective, and finds Helen a sympathetic listener. Then Nicky gets a call from the local pharmacy querying an the incorrect prescription. Nicky confronts Alistair over Helen's inadequacies. He girds his loins to do a telling-off, but he is relieved when Helen heaps coals on her own head.

Meanwhile, Nicky is already forming a theory about Denise - Munchausens by proxy. But when she starts to question Helen, Helen only sees criticism. She niftily turns it back - suggesting that Nicky is uptight. When Helen confides this to Alistair, he agrees. Even though he still holds that tiny candle for Nicky, he sees that Helen is a much more likely prospect. They bond over their mediocrity.

Nicky worries that her concern over the Crouch kids is in fact motivated by dislike of Helen. But when she gets fresh fuel to her fears about Denise, Alistair is unsupportive. He insists there is no proof. Nevertheless, Nicky sticks to her guns and suggests that the kids be taken off their medication, despite Denise's bad reaction. Gil begins to guess Nicky's suspicions, but won't confront Denise.

Nicky hits a rock when Gwyneth seems scared of coming off her medication. However, this turns out to be the proof that Nicky was looking for: Gwyneth hasn't taken her medication for a year, with no ill-effects. Nicky manages to get a good outcome for the Crouch family, but is still distant from Alistair. Helen moves out to stay with him. Nicky has done the right thing - and lost her best friend.

Diane feels William has got off lightly after the Royal Commission and vows he will suffer. However, it seems that William is about to do anything but, when he helps Louise move into the bedsit above the bookshop - and they resume their relationship with cheerful abandon. Louise goes wild and leases a sports car. This doesn't please Diane, who finds William's happiness distasteful. She is even more aghast when Louise is entirely unrepentant about the relationship. But when Ross arrives, angry and armed with knowledge - William sees that Diane has found a way to effect her revenge. Ross thinks that Louise's move is designed to make him feel bad and - if she's going to buy a sports car and disport with William, he is planning to make the matrimonial split ugly. After this acrimony, Louise starts to feel happiness is too much to ask. William argues that she's over-reacting - but realises he needs to make peace with Diane.