The cast list initially grabbed my attention; it’s unusual to see someone as sophisticated as James Mason in a western alongside Lee Van Cleef. However, Gene Martin's direction ultimately fell short of expectations. Mason appears briefly as "Montero," the man who took "Alicia" (Gina Lollobrigida) away from her train-robbing husband, “King” (Lee Van Cleef). Not only did she leave him, but she also had him committed for insanity and made off with his money. He eventually escapes, and they reconnect years later on a riverboat where she explains an elaborate scheme to steal $1m in gold from the Mexican government. Philip Yordan is credited as the screenwriter, though it seems he may have only been involved for a short time because the script itself feels disjointed, overly stylized, and filled with scenes that border on slapstick comedy. Lollobrigida carries the film; she clearly knows what kind of movie she’s in and her performance prevents it from sinking completely into comedic mediocrity. There are some amusing moments—like transforming an old Model T into an armored vehicle by attaching wooden planks—and the Mexican soldiers certainly don't help themselves, seeming incapable of hitting anything even at close range. It moves along quickly and has a somewhat fitting conclusion, but overall the film feels chaotic and struggles to hold your attention beyond its sillier aspects.

Source on TMDB