Doctor Alejandro Mangino falls in love with Lucía just before he goes on a round-the-world trip. Pining for her all the while, he returns to find that she’s married his best friend.
The disaffected wife of a failed civil servant, is thrilled to re-encounter Octavio, a former lover who is now a union activist on the run from a corrupt politician. Hoping to help him, she descends into the Mexican underworld, where she finds a purpose-and a thrill-missing from her married life.