A Wiser Guy tells the evolution of an Italian American Mafia family in the United States during the golden years of the Mafia, the ‘20s through the ‘90s, culminating with its decline at the end of the 20th century. The story is told through the lives of Louis, Ernie, and Paul, three men of three different generations of the Palmeri family.

New Jersey, 1955. The life of Louis, a six-year-old is going to take an unexpected turn. His loving grandfather Paul Palmeri, a founding and highly regarded member of the American Mafia, the man he most admired, has died unexpectedly. Things will not be the same for the Palmeris. Their privileges, influences and income in the world of the Italian American Mafia are threatened by Paul’s death.

Louis makes us travel from the ‘20s through the ‘90s in the lives of members of the Cosa Nostra. In Niagara Falls and Buffalo, during prohibition. Louis explains the beginnings of his grandfather Paul's career in the Mafia through the illegal trafficking of alcohol led by “Buffalo" Bill Palmeri. After prohibition back in New Jersey, Paul must raise a family living an exemplary public life and at the same time developing his darker side in the shadows, that Louis will discover, as he grows up, through jumps in the timeline, back to the past and forth to the present.

When fluctuations in the oil market bring about a recession in the ‘80s, Louis will try to provide for his family and live a life without setbacks. He will strive to detach himself from his criminal origins, but first he must overcome the crisis through illegal “supplemental income”. During the full decline of the Mafia, Louis must make a final decision as to which role he should play in his family's history.