It's 1962. Fifty-nine year old Joe Valachi is convicted for drug trafficking and imprisoned. Inside, someone is out to kill him. He learns that it is his mob boss, Don Vito Genovese, who is in the same penitentiary as him, since Genovese mistakenly believes he was the snitch who put him behind bars. Because of the bounty on his head from his own, a federal agent named Ryan convinces Valachi really to be a mob informant in return for safety inside. Valachi tells a story that starts in 1929, when he was first imprisoned in Sing Sing and met Tony Bender, who introduced him into the life of the mob. Through internal struggles for control of the mob, Valachi remained faithful to the mob family, including through Genovese's reign starting in the late 1930s. As Valachi nears the end of his story, he learns that what has happened in the time leading up to and during his latest incarceration was by no accident, which is all the more troubling to him if only for the safety of his family including his wife Maria, the daughter of a mobster, who he was only able to marry through assistance by Genovese.