"Special friendships" are youthful relationships with homoerotic overtones, and this film explores them in the setting of a strict French Roman Catholic boys' boarding school in the 1930s. The faculty are ever alert, depriving the students of all privacy. When a vulnerable fifteen-year old boy, motivated variously by jealousy, subservience and fear, or genuine good intentions, co-operates with his teachers' campaigns to repress all suggestion of romance or impropriety in his own and others' friendships, he betrays everyone most important to him. Based on the novel "Les Amities Particulieres" by Roger Peyrefitte.

Soon after his arrival at a strict French parochial school in the early 1930's, 16-year-old Georges becomes good friends with a fellow student, Lucien. Upset at discovering a love letter to Lucien from another boy, Georges turns the note over to the Father Superior. The scandal results in the dismissal of the boy who wrote the letter, but Lucien remains in school. As the weeks pass, Georges finds himself increasingly attracted to a younger student, Alexandre. At Lucien's suggestion, Georges begins meeting Alexandre. When their regular meetings are threatened by the suspicions of Father Trennes, a young priest, Georges retaliates by telling the Father Superior that Father Trennes sometimes entertains students in his office at night. Caught one evening with a boy, Father Trennes is immediately dismissed. Before leaving, however, he warns Georges against judging others too rigidly. One afternoon Alexandre's confessor, Father Lauzon, discovers Georges and Alexandre playing and smoking together in a shed, and he threatens to expel them unless they abandon their special friendship. Georges agrees to stop seeing his young friend, but Alexandre has decided that expulsion is preferable to repudiating their relationship. Crushed by his friend's desertion, Alexandre kills himself by leaping from a train that is carrying him home.