Gran Casino (1947)

After the mysterious disappearance of an oil well owner, one of his workers, Gerardo (Jorge Negrete) assumes the business management. Soon, the owner's sister (Libertad Lamarque) arrives from Argentina, and, believing that Gerardo killed her brother to keep the wells for himself, she starts working as a singer under a false name in the same casino her brother disappeared, in order to find out what exactly happened.