Marcel Spadice, author, poet and playwright, is fascinated by the circus which is a source of inspiration for him. With the help of his friend, Hélène Lagache, he manages to seduce a ring-attendant, Franz-Ali Aoussine, who dreams of becoming a star of the tightrope. Marcel takes over the young man's training and imposes a steel-like discipline on him. Franz-Ali submits to the Master's demands, risking his life in the process...