In a typical Latin-American cabaret of a poor quartier of Panama, singers, comedians, conjurers and acrobats perform for a public composed by longshoremen, unemployed, workers and poor people. They are "those of the Barrio", the ones living in the quartier where everybody lives like in any other working-class district, dancing, dreaming, loving and working to the beat of Mambo. But one day, everything changes: a foreign invasion and war. Mambo will not be the same any longer. There is effectively no dialog in this film, everything is communicated through dance or pantomime.