It is about the lives of two Cuban brothers and musicians, Cesar and Nestor Castillo, who immigrate to the United States and settle in New York City in the early 1950s.

It tells the story of Cesar Castillo, an aged musician who once had a small amount of fame when he and his brother appeared on an episode of I Love Lucy in the 1950s.

The book chronicles Cesar’s last hours as he sits in a seedy hotel room, drinking and listening to recordings made by his band, the Mambo Kings.

In telling Cesar's story, Hijuelos weaves in cameo appearances by several real-life mambo musicians, including Desi Arnaz, Tito Puente, Pérez Prado, Machito, and Mongo Santamaría.

Also, the book showcases Hijuelos' distinctive, richly detailed description of his characters' lives written in a prose-style that evokes the rhythms of Cuban music.