The book starts with the murder not of a union official but of a small-time builder and president of a local building cooperative, Salvatore Colasberna. He is shot while getting on a bus for Palermo and, by the time the police get there, the few remaining witnesses saw nothing at all. Captain Bellodi, who is not Sicilian, is put in charge of the investigation. Bellodi faces a wall of silence but persists, even when politicians in Rome try to have him removed. Another potential witness is killed but the witness's widow is able to point him to the killer. With various false leads and other witnesses killed, Bellodi gets nearer to the crime, even interviewing and detaining the local Mafia boss. The matter once again gets to Rome and into Parliament with one senior Christian Democrat maintaining that there is no such thing as the Mafia. The politicians who are, of course, implicated, try to imply that it was a crime of passion or a local business deal gone wrong. Bellodi, increasingly frustrated, ends up by saying To Hell with Sicily.
Sciascia was to write other Sicilian novels, implicating the Mafia, in collusion with corrupt local and national politicians, in a variety of crimes, e.g. A ciascuno il suo (A Man's Blessing; To Each His Own) and with a honest, though naïve investigator struggling to break through the wall of silence, the omertà, often unsuccessfully. However, it is this one that has the deserved reputation as his best, not least because we see not only the honest cop, realizing what he is up against, hoping to break through but ultimately failing, but we also see the Mafia boss, not necessarily a monster, indeed a human being with at least some human feelings, but, of course, an enemy of everything Sciascia stood for.