Dr. Martin Dysart, a psychiatrist at a provincial English hospital, is confronted with a challenging and disturbing case involving a 17-year-old boy named Alan Strang. Alan has been charged with the violent blinding of six horses, an act that appears inexplicable and irrational. As Dysart delves into Alan's troubled psyche, he discovers the boy's complex history, marked by intense religious fervor from his mother and stern authoritarian discipline from his father. Alan reveals an obsessive fascination with horses, which becomes intertwined with his own spiritual and sexual awakening, manifesting in rituals that elevate the animals to the status of deities.

Through a series of therapy sessions, Dysart begins to piece together the events leading to Alan's horrific act. The psychiatrist becomes increasingly captivated by the depths of Alan's passion and the intensity of his psychological torment. Dysart's own sense of purpose and emotional stability are challenged as he grapples with the profound implications of Alan's psychosis. The unraveling narrative reveals deeper questions about normalcy, sanity, and the human capacity for worship and destruction. As Dysart seeks to cure Alan, he is forced to confront his own dissatisfaction with his life and profession, setting the stage for a gripping exploration of duty, empathy, and the boundaries of psychological intervention.