Philip Castle, newly separated from an adulterous wife and afflicted by middle-age doldrums, is a professor at the University of Chicago off to the Caribbean for a relaxing vacation. But life is far from restful. His first day on the island he watches a small plane crash, piloted by a man who looks disturbingly like him. He then meets Marie-Celeste-a fabulously beautiful and provocative young woman with whom he makes love-only to find that she...