At a police station in Milan, Inspector Bertozzo is interrogating a certified madman about a series of frauds. Unfortunately for the policeman, the madman is far more quick-witted than he is, spotting an opportunity to evade the consequences of his crimes and wreak havoc on the police force in the process.
Having outsmarted Bertozzo, the madman impersonates a judge, who is investigating the death of an anarchist. The anarchist apparently fell to his death from a fourth story window at the police station. The police claim he fell accidentally. Or he jumped accidentally. (If that's a thing.)
As the madman begins to unravel the police station’s attempted cover-up of the death, he affects various other personas that help expose the police officers’ incompetence and corruption.