This stunning film is one of a few films made by Adolfo Best Maugard (“Fito Best”), the great Mexican painter. Initially banned under the administration of Lázaro Cárdenas, it was released in a badly censored form for a short run under his successor’s administration but was critically panned and disappeared for the next half century.
A full plot synopsis from wikipedia,
Camelia, a prostitute who works in a seedy cabaret of Mexico City called “La Mancha de Sangre” (“The Blood Stain”), meets Guillermo, a young newcomer from the provinces who is in search of a better future. She provides a place to stay for the impoverished unemployed young man until he can establish himself and their initial friendship soon turns into love, a situation that does not win him any favor with Gastón, Camelia’s pimp, who, upon learning of the affair, teaches Guillerma a lesson to drive him out of the girl’s life.
Eventually, Guillermo returns to the cabaret but, to the surprise of Camelia, he now no longer appears dressed in his usual work clothes but in a flashy gangster suit because he has joined the gang of a jewel thief known as “The Prince”. He will soon be making a big score so Camelia, fearing that the job will go wrong, finds out when they intend to commit the robbery and rents an apartment of her own. Just as Guillermo is on his way to meet up with his boss and the rest of the gang to do the job, the prostitute takes her lover to this new love nest and convinces him to spend the night with her.
Now, just as Camelia had guessed, the police end up arresting the Prince who is forced to confess to whom he had sold the stolen jewels to Camelia’s pimp. An officer apprehends Gastón, but he manages to escape and flees to Camelia’s place where he threatens to kill her. The police catch up with him there and a shootout ensues resulting in the death of the pimp and now both Guillermo and Camelia are able to start their new life together.