Marty finds somebody digging around his grave. He sends Jeff to investigate the cemetery and in doing so is knocked unconscious several times by a masked 18th century axe wielder. Suspecting the gardener, Jeff accepts a job for a wealthy man in the nearby mansion and stumbles on an intricate plot to steal his insane agoraphobic son through an underground tunnel pretending to hold him to ransom. It is all part of a plot to inherit his father's fortune but when he marries his young housekeeper the plan is demised. Geoffrey Hughes appears as Harper. Also Andrew Sachs, appears in a small pre-Fawlty Towers role as the English commentator during the first leg of the international football match that Marty goes to watch.