Plot: The clerk Otto Bertola hires Nero Wolfe to prove that the woman who has circuit and married the fragile son Lapo, the seductive Susanna, damaged his business together with Silk, just dismissed secretary. To investigate Archie Goodwin moved to the villa of Otto under cover as a new assistant; so he knows what Bertola calls "parasites": Lapo and Susanna, who seem to really love each other; his second wife, Trina, dedicated to alcohol and men; her brother, Ruggero, maintained with a passion for the game