A 17th century woman, imprisoned for fighting in a bar, recounts her past to a priest. She tells of her father teaching her how to fence, of being sent to a convent by her aunt when her father died, of escaping by dressing as a man, and of her life as a man following the escape.

María Félix
as Catalina de Erauso

Ángel Garasa
as Roger

José Cibrián
as Juan de Aguirre

Delia Magaña
as Elvira

José Pidal
as Don César, canónigo

Fanny Schiller
as Doña Úrsula

Paco Fuentes
as Don Miguel de Erauso

Eugenia Galindo
as Doña Cristina

Esther Luquín
as Beatriz

Maruja Grifell
as Reverenda madre