While Gaetano, Torre, and Camilla are in the apartment with Gigi and Renato, their grandmother returns and is frightened upon seeing the police. Chaos ensues. Back home, Livietta has another pet proposal for her father, who is trying to multitask.

The news of the American tourist's murder is broadcast on television when Camilla returns home and finds Renzo very agitated about his project, which, according to him, is missing something.

Gaetano has to discuss the wedding with his fiancée, who wants to contact his professor friend for some information about bullying at school. At work, Renzo is updating everyone on his new ideas for the project.

There's a bit of chaos in class between Aiello and some classmates, Camilla is forced to calm things down. The victim had purchased some diamonds that have disappeared.

Gaetano meets Camilla at school, before Renzo gets there, to ask her a favor. Both seem to want to hide something from their respective partners. Gaetano and Torre talk to the jeweler again.

Livietta tells Camilla that her grandmother promised to give her a tropical fish. Renzo and Camilla don't see eye to eye on the idea. Meanwhile, during the search at Aiello's, Torre finds something.

Renato is questioned after one of the diamonds was found in his room. Camilla wants to believe he is innocent until proven otherwise while the principal already thinks he is guilty. Meanwhile, Roberta will meet Camilla for dinner.

Livietta is still trying to figure out how to convince her father to get a fish. Camilla, before going to dinner with Roberta, stops by to say hello to Renzo who is struggling with his project.

Camilla is finishing dinner with Roberta and Renzo is about to leave to pick her up when he is stopped by Andreina who wants to try to convince him to reward Livietta. At Hotel Bisanzio, Camilla and Roberta encounter a somewhat embarrassing situation.

After dinner, the two couples meet a colleague of Renzo's who also happens to be the boyfriend of the victim's sister, Meg.
The next day, Gaetano and Torre speak again with the suspect, and Camilla is present as well, with her student.

During Nando's interrogation, a detail finally emerges that Gaetano can then investigate. After speaking with the suspect, Gaetano goes to visit Meg, the victim's sister.

When Gaetano meets Meg, he tells her that her sister Holly had been in a relationship with Marinetti. Camilla goes to see Renzo at his studio and gets some shocking news.

From talking to Camilla, Gaetano connects some dots and rushes to the hotel to talk to Meg right as she is leaving.

After Meg's confession, Gaetano and Camilla go to dinner to discuss the conclusion of the case. While talking, Gaetano asks Camilla something but at that moment she receives an emergency phone call from home and rushes off without answering.