To make pasta, only 2 ingredients are strictly necessary: semola (durum wheat flour) and water. But atmospheric conditions make all the difference.

Alessandro explains some things about the characters in his books and tells a story about when he won the Strega award. The Strega Award is the most important Italian literary award. It gets its name from one of its creators, the owner of the company producing Strega, a brand of an amaro (after-dinner, digestive bitters).

Renzo comes home late after a meeting and finds Camilla on the couch deep in thought. She lets him know she has been connecting the dots between the postcard and the merengue instructor. She goes off to bed but finds a surprise on the way.

At the hotel where Aragona stays, he tries to find out who the new housekeeping person is. Down at the police station, there is news concerning the prostitute Varricchio says he spent time with the night of the murder.

Italy is known for its pasta. The Zampino family was able to give new life to an old flour mill from the sixteen hundreds and turn it into a productive plant where they produce pasta keeping to traditional methods.

Leaving the outskirts of Rome, Annalena goes to a middle-class neighborhood where she meets professor and writer, Alessandro Piperno. He talks about what it was like growing up there and about his identity as a writer.

Lojacono goes to Letizia's trattoria and tells her about the bad news about the witness. She tries to reassure him but also has a new customer to attend to. Francesco can't let Giorgia go and sleeps in the car in front of her house.

How are the harvested truffles divided up? And besides being sold whole, how are they further processed? Paolo and Stefania tell us the story.

Melania Mazzucco grew up in a part of Rome on the outskirts, not the part people usually associate with the beautiful city. The white Fiat 500 her father bought for the family became an important part of her life.

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.

Varricchio is back in the DA's office and tells a different story, admitting he had lied the first time. But is there proof of his new version? At home, Lojacono is shocked by some news he hears on the TV.

Truffle hunting is a peculiar activity, one that requires the collaboration of a dog. And you never want to let on how many truffles you find, even if you are friends with other truffle hunters.

Melania talks about her relationship with her father when he was still alive. He didn't say much, but unbeknownst to her, tried to get a story of hers published. She talks about one her favorite parts of Rome: Isola Tiberina (Tiber Island), the only river island in the part of the Tiber that runs through Rome.

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.

Ottavia and Palma talk about his new apartment and the fact that it is still empty. Lojacono gets some good news from his friend Paolo and shares it with Marinella. He goes to the train station to wait for Laura and gets an idea about the case.