After her trip to the Tiber River, Camilla goes to pick up Livietta at Giulio's house, where the two kids are dancing to Merengue. Camilla has some questions about that. Meanwhile, Berardi and Torre are busy with the coroner, identifying a corpse.

The mouse is still an issue at Camilla's house. At police headquarters, Berardi has his hands full with the mother of the murdered detective and Mattioli's wife.

Camilla, in conversation with her mother, hopes that the postcard from New York is just a misunderstanding. Renzo has a moment of truth by a dumpster. Later, he says something about Dr. Mattioli that gives Camilla an idea about her "hallucinations."

Camilla can't help herself and goes to the home of Mattioli's former nurse. Gaetano leaves Camilla a text message. Note that in Italy, texting while driving is now prohibited.

Camilla is still convinced there is a mouse in the house and Renzo humors her. At school, there is some tension, but Marchesi has some information for Camilla and her mood changes. Berardi also obtains, almost by accident, some intriguing information, that could be pertinent to the case.

The detective's mother is not able to provide any useful information to the police. Renzo finds a small object near the front entrance of their apartment building. He also gets a postcard from New York, causing not a little stress to Camilla.

Camilla can't rest until she has reported her suspicions to Berardi, and goes down to the police station before school.

Camilla ventures up to Doctor Mattioli's office to see if the nurse is there and to ask him about hallucinations. At the police station, Piccolo is making an effort to make Ferrari like him.

Livietta tells Camilla about the scene where Giulio used a word he shouldn't have and was scolded by Renzo. Camilla is still seeing the mouse. The coroner reconstructs the murder for Berardi.

Camilla is still upset about what she thinks she saw during the night and goes to see Gaetano. Renzo goes to pick up Livietta at dance and can't help conjuring up the memory of the merengue teacher he had been attracted to.

Camilla is still confused in the morning, and Renzo has her read the information sheet about the sleeping pills she is taking. Berardi, Torre, and Ferrari are at work going to a new crime scene.

We begin a new episode featuring Camilla the schoolteacher who likes sleuthing, in the middle of the night, when she hears a noise upstairs. Going back to sleep doesn't seem to be an option.

Berardi, the DA, and Torre, along with some of the gutter punks, visit Scortichini at the hospital. Words are exchanged, and Berardi manages to get some answers. Back home, it is time for the birthday party, where Renzo has to make balloon animals for the kids.

The gutter punks are at the police station, but don't want to talk, so Berardi lays out his idea of what happened. At a certain point, Camilla shows up, too.

Torre, Berardi, and Ferrari go to the farmhouse where they find some evidence relative to the murder. Camilla admits to her mother that she is a bit jealous of Renzo being out to dinner again.