Based on the book of Benito Pérez Galdós. Marianela (Nela) is an orphan young girl living in a small village where she guides the blind young son of a rich country man. She is secretly in love with him, knowing that he loves her only because he can't see her ugly face. But one day a famous doctor appears and promises to operate him so he can see. His father is happy to know this way he will be able to marry his rich cousin. Nela gets desperate knowing his luck will turn into her disgrace when he finally sees her face.