When Maria Grant (played by Claudia Cardinale) is kidnapped by a Mexican revolutionary, her Texan millionaire husband hires four gunmen to rescue her in this important step in the evolution from the classical Western to the genre's later, post-heroic incarnation. Just as The Professionals would be unthinkable without the early work of Sam Peckinpah, Peckinpah would acknowledge the debt to Brooks’ epic adventure with The Wild Bunch. The western’s evolution in the 1960s included an aesthetic shift from the Technicolor brilliance of the 1940s and 1950s to dustier and more muted colors, evoking a more realistic vision of the frontier and its moral ambivalences. Master cinematographer Conrad Hall displays a genius for the postclassic color tone of the modern Western.