The beast must die was a brilliant film.When Marlene Clark had finished filming,she went straight back to America.Unfortunately,Calvin Lockhart missed her so much,he could not act for the remaining duration of the film.Calvin caved in and went back to America.The film was not finished,and Calvin kept refusing to come back to finish it.Eventually,Calvin was persuaded to return to finish the film,which was basically the car chase with Michael Gambon scenes.