A Parisian couple decides to sell an unsanitary basement in their building. A very ordinary, nondescript man, Mr. Fonzic, shows up to buy it. Nothing unusual there, until the man moves into the cellar and makes it his permanent residence. The couple tries desperately to cancel the sale but to no avail. Worse, Mr. Fonzic becomes a threat to their family as he befriends their teenage daughter on whom he seems to exert a perverted influence.
Elenco: François Cluzet , Bérénice Bejo , Jérémie Renier , Jonathan Zaccaï , Martine Chevallier , Jack Claudany , Antoine Levannier , Victoria Eber , Denise Chalem , Patrick Descamps , Ambroise James Di Maggio , Sacha Attal , Sharif Andoura , François-Eric Gendron , Laëtitia Eïdo , Patrick d'Assumçao , Éric Génovèse , Candice Bouchet , Jean-Claude Frissung , Nicole Gueden .