A series of hideous murders follow as the devil protects his own .
But , retaliation is swift and brutal , in the guise of Sir Robert Knight ( Peter Wyngarde ) and his equally lethal lawyer , Dunboyne ( Jason Connery ) .
A series of hideous murders follow as the devil protects Robert Knight 's own .
But , retaliation is swift and brutal , in the guise of Sir Robert Knight ( Peter Wyngarde ) and his equally lethal lawyer , Dunboyne ( Jason Connery ) .