Marianela tells the story of a poor orphan girl with an ugly face, and her love for Pablo, a blind boy, who also has romantic feelings towards her. Marianela frequently sings to Pablo, and he believes she is beautiful because of her voice and wild yet intelligible imagination. Pablo's father asks a famous doctor, Teodoro Golfín, to examine Pablo to determine if his sight can be obtained. Pablo, full of hope at the prospect, promises Nela that he will marry her after the operation, if successful, but the arrival of Pablo's beautiful cousin Florentina changes the dynamic in their relationship.

Benito Pérez Galdós (1843-1920) was a Spanish realist novelist. Some authorities consider him second only to Cervantes in stature as a Spanish novelist. He was the leading literary figure in 19th-century Spain. He remains popular in Spain, and is considered as equal to Dickens, Balzac and Tolstoy. While his plays are generally considered to be less successful than his novels, Realidad is important in the history of realism in the Spanish theatre.