Ann starts a reform period. Joan has had enough of prison work, takes leave of absence to search for a new career, but not with much success. She is quickly fired from a restaurant job. It looks more promising at a security company, but Joan gets a shock when she discovers that the manager is a former Wentworth prisoner, namely Willie Beecham, who has gained big influence and sabotages Joan's further job searching.
Spider outmaneuvres Kath and takes over the shop. Marty tries to find proof that clears Spike. This is not appreciated by gangster boss Ron Willis. He makes an offer to Kath, who once again is frozen out by the other women. Kath drugs Spike with heroin and manages to put the blame on Marty who is suspended. As thank she is helped by Willis to escape, but in the hurry she doesn't get her friend Merle with her.
Because of Willie Beecham's influence, Joan gives up her efforts to find a new job. She re-enter her position at Wentworth, as mean as ever. As part of Ann's reform plans, radical teacher Tom Lucas arrives at Wentworth. After a confrontation with Rita, Spider is transferred to Barnhurst. Rita collapses and is taken to hospital, where she is diagnosed with cancer and only small chances to survive.
Willis orders Kath to be killed. However she escapes and tries to contact Merle, who has been taken to mental hospital. Merle doesn't want to know of Kath, who instead is arrested and returned to Wentworth. Kath confesses everything, Marty is given his job back, Spike is released and Merle can return to Wentworth. Brumby, who knew about Kath's escape plan, is frozen out by the other women, but she soon finds a new ally in Vicki and they begin to smuggle in goods from Spider at Barnhurst. The released Lisa has spied on and ridiculed Rodney, and he retaliates by having her arrested on false grounds and she is returned to the prison. Alice has a romance with one of the male prisoners from Blackmoor, Harry Grosvenor.
Rita accepts her fate and instead begins to create a plan to definitely get rid of Joan. The first step is to unite all women to make Joan desperate and vulnerable. As a part of this plan Rita makes peace with Kath. When the women's resistance has influenced Joan, Rita advances to the second step in her plan. She offers Joan half of the prey from a burglary at a finance company. Joan tries to break the women by bashing Lisa, who has been the most insubordinate, but this only contributes to an even more united front among the women. Joan, who is now completely ignored by both colleagues and prisoners, accepts Rita's offer. She lets Rita escape to make the burglary at the finance company. Rita hides the money in the building and lets herself be arrested at the spot and is returned to the prison. Back there she resigns as top dog and surprisingly suggests Kath as her predecessor. This is accepted by the women after Kath has proved her capability by putting Rodney in his place.
The next day, Joan is informed about Rita's death during the night. She now dares to go to the finance company to collect the hidden money. The police have set a trap, she is arrested and taken to Wentworth pending further transfer. Meg, with Ann in the background, inducts Joan at the reception and takes her to isolation. The news reach the prisoners and a hysteric happiness breaks out. At dinner time, the tray is taken to isolation by Rita and Joan realizes the trap she went in. Next morning Joan is due for further transfer. Prisoners and staff are all witnessing the departure. When the police car leaves the area a spontaneous cheering breaks out. Rita pronounces the last classical lines, that she will fight the disease and "be the oldest biker in the world."