Merle Jones was introduced when Joan arranges her transfer from C block as muscle to support Kath Maxwell, who Joan is trying to set up as top dog on Wentworth. It is stated that Merle should not really be in prison at all, but in some other secure institution. Her low mental age gives rise to her nickname "Loony", but she is not mentally ill, though her confusion often expresses itself violently. Although she may be being Kath's protector physically, emotionally she becomes a substitute daughter for her, and this aspect of their relationship is well handled and manages to be touching without being over-sentimental. When she is utterly betrayed by Kath when Kath abandons her during an escape attempt, Merle has a breakdown and is transferred to Ingleside mental hospital. Marty Jackson is mainly responsible for her recovery and return to Wentworth, where she is reconciled with Kath in the penultimate episode.