After a young man is killed in an unexplored subterranean cavern and his girlfriend driven mad by something she saw there, a track found at the scene cannot be identified with any known animal and thus a scientific expedition is launched to find out just what it is that is living there.

Un joven estudiante es asesinado por la banda de Los Puñales. Su hermana, la maestra de química Rosa, novia del agente policiaco Lince, se desespera por la pasividad de las autoridades y decide intervenir. Usa una motocicleta y un traje que le pertenecieron a su padre acróbata. Localiza a los delincuentes disfrazándose de cabaretera y va matando uno a uno.

The building of a railroad under tough conditions from searing heat to freezing cold in the Sonora desert provokes clashes of passion and struggles between the engineers and the workers at the campsite. The workers also contend with sudden dust storms that are called the 'black wind'. Based on true events.

After getting out of jail, car thief Ernest "Stick" Stickley witnesses the murder of his friend Rainy during a drug deal. To avoid getting killed by the same people, who work for mobster Chucky, Stick gets a job as a chauffeur for millionaire Barry Braham and lies low. As he gets used to his new routine, Stick woos Barry's financial consultant, Kyle McClaren, but must fight back when Chucky's men come after him.

Small-town doctor bitten by rabid dog, races the clock to get to the city and receive treatment.