François Karwitch is a young lawyer from a wealthy but stifling Jewish family. His life is meticulously ordered, he does his routine work day after day and is about to marry Fanny, the fiancée forced on him by his parents. One day, from the window of his Brussels practice, he witnesses a scene which will turn his life upside down: the brutal internment of a man in a nearby psychiatric hospital. Shocked by the treatment given to this person he decides to learn more about him. His name is Carlos; he is a revolted blue collar; and if he has been taken to this place, it is because he killed the head of an arms factory.