NEW YORK, NY.- Marc Jaffe was at a New Year’s Eve party of Hollywood types in 1967 when a screenwriter named William Peter Blatty began chatting him up. Blatty said he had tried and failed to sell an idea for a novel – about a young girl possessed by the devil and the tortured priest who tries to save her. But Jaffe, editorial director of Bantam Books, a paperback publishing house in New York City, thought the idea sounded pretty good.