This work investigates the internal mechanics and moral decay of the American Mafia through the testimony of Salvatore "Sammy the Bull" Gravano, the highest-ranking mobster to ever turn government witness. Author Peter Maas utilizes extensive interviews and investigative reporting to document Gravano's rise within the Gambino crime family and his eventual decision to cooperate with federal authorities. The narrative provides a detailed account of the power structures, illicit operations, and pervasive culture of violence that defined the Cosa Nostra during the late twentieth century.

The book is regarded as a definitive, albeit controversial, primary source document that provides an unprecedented look into the inner workings of organized crime. Its clinical yet gripping examination of Gravano's life serves as a significant historical record of the decline of the traditional Mafia in America.