The year is now 1954 and the sleepy Cotswold village of Kembleford sees new faces join Father Brown's team of sleuths. The dashing Chief Inspector Sullivan is back and proves a pleasant distraction for Mrs Devine, Father Brown's lively new Parish Secretary, while plucky new housekeeper Brenda helps the priest's crime solving.
Father Brown discovers that a murderer is using Kembleford's new model village to plan their attacks. He also needs to find a new secretary following Mrs McCarthy's departure.
The visit of Princess Margaret to Kembleford is jeopardised when a school janitor is found murdered. Can Father Brown save the royal visit from being cancelled?