This is one of the key titles from the classic period of Mexican horror, a period which was low on quantity but surprisingly high on quality. It precedes the two best-known films of the cycle, "Dos Monjes" and "El Fantasma del Convento", and shares some key personnel with them. La Llorona is a figure unique to Mexican folklore -- the wailing spirit of a woman who lost or killed her child and now returns to seek revenge and haunt the living. With its framing story and flashback structure, this film sets forth a couple of variations of the story. It is well-shot overall, with fine sets and shadowy photography (reminiscent at times of early US talkies like "The Bat Whispers"), and the scenes of the Llorona and her agents are often visually (and aurally) striking in their crude way. However, the bulk of the movie tends to be somewhat pedestrian and melodramatic, and it can't compare with the stylistic triumphs of "Monjes" and "Fantasma". As the first of the genre, though, it warrants plenty of admiration and respect. Also fascinating is the mixture of the "pagan" beliefs of the indigenous culture with the Catholic morality and ethics of the bourgeois classes, a contrast which would appear often in Mexican films. A later 1960s telling of the story (with the same title) fashions it more as a Gothic vampire piece, and is one of the finest contributions to the Latin horror revival of the time.