During their hour of detention, Paul, Enzo and Gabriel expect to copy lines but their biology teacher, more perverse than ever, improvises a practical course of anatomy before inflicting them a punishment from another time. The innocent Gabriel Lambert is called to undress in front of his hilarious classmates to be used as an anatomical model in a true feat of exhibition. The high school student embarrassed by this unexpected situation shyly takes off his shirt but his teacher expects more. Gabriel blushes again and tries to argue when Mr. Marguet joining the gesture to the word drops down his pants and his underwear. The young man is now completely naked in front of his class and his teacher begins to describe his anatomy.