His wedding just weeks away, Agnes Brown's son Dermot has to pick his best man. Dermot wants to ask childhood friend Buster, but Mrs. Brown is concerned that Dermot's fiancée Maria won't approve of this choice - Buster has a well-deserved reputation as a criminal. On top of this, Mrs. Brown is distracted by another crisis: her friend and neighbour Winnie is distraught because her husband Jacko has been rushed to hospital. Winnie needs to raise money for Jacko's operation and Dermot needs to raise money for the wedding. Unfortunately, Dermot's solution is to get involved with one of Buster's stupid money-making scams.