A prominent London Psychologist seems to have taken his own life, causing stunned disbelief amongst his colleagues and patients. His teenage daughter refuses to believe it was suicide as this would go against all of the principles her father stood for, therefore she is convinced it was murder. She enlists the help of a former patient to try to get to the truth. The truth, however, turns out to be both surprising and disturbing.
Dr. Leo Whitset, an eminent London psychoanalyst, is found dying from a gunshot wound in the consulting room of his home. He is discovered by his housekeeper, and a few words whispered to her before his death leads the coroner to pronounce a verdict of suicide. Dr. Whitset had restricted his private practice to a select group of patients and devoted most of his time to teaching and research. Alex Stedman, an American TV news commentator who had been one of Dr. Whitset's patients, believes that the death was not a suicide. Catherine Whitset, the 14-year-old daughter of the dead man, visits Stedman and pleads with him to find the person responsible for her father's death. From memory, she supplies Alex with the names of the doctor's three other patients: Sir Frederick Belline, a judge; Alfred Price-Gorham, owner of a London art gallery; and Anne Tanner, a London secretary. Alex visits each of the patients in his search for the murderer and realizes that he, like the other patients, has a secret self known only to the murdered man. He accidentally learns from Catherine that there was a fifth patient, and he goes to the doctor's country home where the dead man kept his files. He learns that Catherine was the fifth patient, and she confesses that she killed her father to prevent him from sending her to an institution to be treated for schizophrenia. During a reenactment of the crime, Catherine stabs Alex. After he recovers from his wound, he visits her at the institution and promises to remain her friend.
