When Mallory's pursuit of a fugitive ends in disaster, a familiar face returns to hunt the culprit. Alan Tylett, suspected of killing a police officer, is seen near Kembleford — and Inspector Mallory is determined to catch him no matter the risk. After Sergeant Goodfellow is shot, Mallory reluctantly asks for the help of Father Brown. With Mallory in hospital, Divisional Chief Superintendent Len Blaisen takes charge — whilst his son Constable Colin Blaisen is more interested in seeing his fiancee Alice Bonham, who also happens to be Goodfellow's nurse.