Tras una larguísima persecución más allá de las fronteras de Estados Unidos, el forajido Butch Cassidy fue asesinado junto a su amigo Sundance Kid en Bolivia, en el año 1908. Al menos eso dijeron los periódicos. Porque la realidad es distinta: Cassidy sobrevivió al tiroteo y ha permanecido escondido durante más de dos décadas. Ahora se plantea volver a Estados Unidos y recuperar parte de lo que le quitaron las autoridades. Por el camino se cruzará con un joven ingeniero español que ha robado la mina donde trabajaba, propiedad del empresario más importante de Bolivia...
Ready to quit their life of crime, the three "most-wanted" outlaws in the West---Butch Cassidy, Sundance Kid and Bill Carver ---perform their final job by robbing and stealing a train and fleeing across the border. In a South American town they begin their life of respectability by purchasing a ranch and depositing their stolen fortune in the local bank, and throwing a big fiesta to entertain the locals, including Colonel Aguilar and his beautiful daughter Rita.
The girlfriend of the Sundance Kid is on the run, with a price on her head, when she hears rumors that Sundance may still be alive.
The historical account of outlaws Butch Cassidy and the Sundance Kid, whose turn of the last century exploits made headlines, led them to be pursued by Pinkerton detectives hired by the railroads, and inspired a hit 1969 film.