Professional killer Holland is forced out of retirement to break a Central American government's political torture ring when one of his friends, a Latin American journalist, is killed. The murderer, Doctor Clement Molloch, is the master sadist behind the political torture of innocent victims. Posing as a journalist, Holland lures Molloch out of his fortress-like headquarters by using his murdered friend's wife and daughter as bait. When Holland kidnaps Molloch's sister, the doctor is led on a wild chase that takes him to an abandoned opal mine where he finally comes face to face with Holland.

Various musical episodes make up this film-magazine in which Del Carril tried to merge his two great passions: cinema and tango.

Torn between three lovers and bored by her typewriting classes, Carolina (Dillian) writes a passionate love letter to fictional Pablo Garza from Monterrey. The letter is sent by mistake and received by real Pablo Garza's girlfriend. Pablo himself (Infante) flies to Mexico City looking for an explanation. Carolina is rehearsing a musical show for her school dressed as a man. When Pablo meets her, she pretends to be her brother Anibal, a shy and feminine sailor. Pablo likes Anibal and invites "him" to a cabaret. After that, Carolina falls inlove with Pablo but resists to unveil her real self. Meanwhile, Pablo feels himself confused, because young "Anibal" is cute as an angel and has "those blue eyes..."