Keir Dullea worked only for a week on this film, never meeting Margot Kidder and barely meeting John Saxon, but the film is edited in such a way that he appears to be present throughout. The role of Mrs. Mac was offered to Bette Davis The role of Peter was originally offered to Malcolm McDowell, but he turned it down. The role of Lieutenant Fuller was originally supposed to be played by Edmond O'Brien, but due to failing health he had to be replaced. John Saxon was brought in at the l ...[Read Story ]