 In the novel Mrs. Iselin had been sexually abused by her father as a child.Before the dramatic climax, she uses her son's brainwashing to have sex with him.Concerned with blowback over even a reference to such a taboo topic as incest in a mainstream motion picture of the time, the filmmakers instead opted for Mrs. Iselin to simply kiss Shaw on the lips to imply her incestuous attraction to him.