In Hermosillo, don Manuel Benavides’ hired ruffians have thrown Kit Willer into a cell at the hacienda of their master, who at that moment is traveling on his dirty opium trafficker business. However, they did not take the pards into account, who conquer the ranch and wait for the Mexican federal police with whom they are allied. Unfortunately for our heroes, the wicked Benavides arrives at the farm first, with a healthy group of hangers-on! Thus a ferocious siege begins, which is only interrupted by the providential arrival of the federal police.