Four retirees in their eighties from a quiet rural community meet once a week to discuss unsolved murders. Elizabeth, Joyce, Ron and Ibrahim call themselves the "Thursday Murder Club". One day they hear that a real crime has been committed in their town: the town's builder has been murdered, and a mysterious photograph has been found next to the body. The Murder Club immediately springs into action. The number of bodies soon increases. Will the brilliant foursome manage to identify the murderer before it's too late?