Commissario Manara is back, this time in a hotel room with leaky water pipes. But he's off to solve another murder case which seems to have something to do with music.

As soon as Ginevra arrives at the scene of the crime, she seems to feel ill. It also seems that Poggiali had been quite a ladies' man.

Commissioner Manara goes to the victim's house with Inspector Rubino, and meanwhile two police officers summon the band leader for questioning.

The band members are interrogated one by one at police headquarters.

The murder weapon has been identified by Inspector Rubino, and she has a nifty program to discover the password for the victim's handheld organizer, found at his house.

Lara's aunt Caterina goes to police headquarters to show Commissioner Manara a painting she found at a flea market, that could help with the investigation.

Manara questions the woman who painted the picture of Lorenzo and gets some further information from the notary's wife, regarding the boat builder.

The rehearsal for Lorenzo's funeral gets interrupted by Manara and Toscani who want to question Scudieri, the bass drum player. Meanwhile, Lara is trying not to explode with anger about Manara's handling of Ginevra Rosmini.

Sardi wants to comfort Toscani after he'd been punched in the face by the bass drum player. Manara wonders where people go in the evening, and Lara, after seeing the Commissioner in a car talking to Ginevra, goes home and confides in her Aunt about why she can't stand him.

Lara decides to question the medical examiner Ginevra, the last person to have seen the victim alive. Manara had a different idea about how to handle his witness.

With the information given by Ginevra, Luca and Lara go to the pharmacy to find out about recent sales of two drugs. When combined, the drugs are fatally poisonous. That same day the funeral takes place and the whole town is there. Manara takes advantage of this to look for new suspects.

An important new element in the investigation comes into play: some romantic letters found at the victim's house. Lara is comparing the handwriting to that of the note found next to his dead body.

Commissioner Manara and Inspector Rubino figure out who wrote the love letters and Lara conducts the appropriate interrogation.

In the presence of Ginevra who has come to thank both Lara and Manara for saving her reputation, they look once again at the painting of Lorenzo. A detail gives them the key to finding the murderer!

At this point the murderer is easily discovered and just as easily confesses. The evening of the murder gets revisited and all previous doubts vanish. But what's to become of the killer?

Although Commissario Manara's has resolved the case, his unorthodox methods are unacceptable to his superior, who threatens to have him transferred to the hinterlands of Sardinia.

In the end, Lara decides that Luca Manara isn't such a bad commissioner after all. She might even tell him that to his face... sooner or later.