Psychiatrist Martin Dysart receives the most difficult assignment of his professional career: he must treat a young man who has committed an act of heinous brutality. The boy, Alan Strang, has been arrested for gouging out the eyes of half a dozen horses he cared for in a stable. From here begins a detective investigation of psychoanalytic overtones in which the psychiatrist must find out what led a young man from a good family, who had never given a problem, to commit such an act. Following the rules of the psychological thriller, the psychiatrist investigates the boy’s life, with a devout and religious mother and a strict and hard-working father.

The sublimation of sexual desire, the lack of relationship with other young people of his age and his fascination with horses are revealed as clues in the mental labyrinth in which the psychiatrist enters to help his patient. But the doctor himself will also have to fight his own demons, among which are a meaningless marriage that does not work and permanent doubts about the usefulness of his profession against the dictates of a castrating society that annihilates the dreams and illusions of people.