The great fadista, Amelia Rodrigues, made her screen debut in Capas Negras, which took its name from the black capes worn by the students in the university city of Coimbra, where the film is set. The action begins in a tavern where a group of former students are reminiscing about their time at the university. One of the students, Jose Duarte then breaks into song, performing an impromptu fado in the local Coimbra style. The tavern owner's niece, the aptly named Maria Lisboa promptly retaliates with a fado of the Lisbon variety. The melodramatic plot then centers on the frustrated romance between these two characters, and the soundtrack is essentially a musical duel between these two different styles of Portugal's national song.

Adriana, an orphan who has been raised in a well off family, becomes pregnant after being seduced by a man. Outraged, Mr. Bento kicks her our of home. What he doesn't realize is that her seducer is his own son, Raul, a brilliant law student.

Maria starts working in the school of a small town. The count starts to feel attracted to her, but she holds a secret she doesn't want to share.

Traveling by car to Sintra, a mysterious lady, arriving in Lisbon by ship, is the victim of an accident.

The vicissitudes of a bourgeois family and the conflicts emerged between brothers - Dr. Manuel Bernardo, wise and weighted, and Zecas, libertine and Capricious - who ignore his kinship. Two girls mark the sentimental vector: one defends the danger that threatens the threat, the other does not know how to react and is the victim of her ingenuity, a dream of restless youth ...