 When Jeanne hears from Mimi singer Isabella A has rented an apartment across her street and would be separating, she spies the room but blames the ignorant students. After Jeanne lectured her for being a troublemaker, Ria manipulates Jo to get a fight over his girlfriend Annick with Dieter and Betty with Lus over a letter from a common acquaintance. Once they realize her game, the four make up and concoct a vengeance using the bunny-cake Jeff had his gullible friend Odilon bring over, neither understanding what it is nor that it s for his own birthday.