Rogelio’s story, a young man of humble origin in the neighborhood of Tepito, who falls in love with the daughter of a wealthy grocer, Michelle, but his marriage to her will be a failure and he will end up as a one more drunk.

Rom-com anthology movie with three anecdotes.

She has an incurable heart condition, her son's a shoplifter, her husband's an alcoholic, her daughter runs away from home...

David is in love with his neighbor Rosalba and follows her everywhere. Rosalba, heartbroken because her boyfriend left her, decides to marry David.

A movie divided in two segments, the first "La puerta" (The Door) is about a high society gathering in which a door inside the mansion leads to a bizarre corridor where a naked and menacing human figure appears. The second "La mujer del carnicero" (The Butcher's Wife) is set during the Mexican revolution and is about horrifying hallucinations felt by a lieutenant after committing a murder.

"Luz Externa was one of the most ambitious productions of the Mexican super 8. The script is based on the monologue of Ernesto, a jipiteca machín, who tells a friend of his mystical adventures with his girlfriend [...] What was probably the super 8 film that best portrayed the countercultural world of the first half of the seventies in Mexico was not seen in its time, despite the expectation that its filming caused in the press." - Álvaro Vázquez Mantecón, El Cine Súper 8 en México