After wealthy master electrician Salvatore Chiarotti is found dead, three policemen—Inspector Giorgio Solmi, Lt. Luigi Caprara and Officer De Luca—investigate.

Solmi and Caprara visit retired madam "Baronessa" Isidora Grimani, who has connections to Chiarotti, and when they discover she's running a brothel out of her estate, they offer her immunity for information.

Caprara and De Luca keep watch over Chiarotti's villa overnight and witness a man break in and attempt to steal tape recordings.

Afterward, Mr. Martinetti tells Solmi that Chiarotti sold blackmail tapes on his wife to him, which he then purchased in order to sever ties with her.

Raimondi's captors say she must confess to killing Chiarotti or die, further bribing her with money and the promise of a short prison term.

Solmi and Mannino discover that a mysterious non-inmate killed Massù, and they go to Martinetti's estate to confront him but are told he has flown to Kuwait.

De Luca investigates a bowling alley robbery and is murdered in a hit job intended to kill Solmi.

Solmi and his men travel to the camp, where paramilitary forces are training, and someone sets fire to secret documents before escaping in a patrol car.

Sperli refuses to reveal the names of the other conspirators and is suspended by the police department and charged with murder, illegal dealing of military weapons and conspiracy to commit crimes.