Zé Luís, a hard-working man of Madragoa (popular district of Lisbon), loves Clara, the daughter of his godfather, the rich merchant Santana. Santana is rich enough to impose Zé Luís to marry a girl of his low social condition, Margarida, and to terminate Luís' employment at his shop, forcing him to work even harder at the docks. Santana goes bankrupt, Margarida dies of a disease, the parents of Zé Luís return very rich from Africa, and Zé Luís can marry lovely Clara, and help his godfather out of debt.