Frank Harris is a Chicago hotel clerk who dreams of making his fortune in the cattle business and has fallen in love with Maria, the daughter of hotel guest and Mexican cattle baron Señor Vidal. When Señor Vidal finds out about the relationship, he orders Harris to stay away and arranges to return immediately to Mexico with his daughter. Tom Reece finishes his cattle drive and takes over an entire wing of the hotel, as usual. He makes a deal to buy cattle from Vidal in Mexico. However, when Reece loses his money in a poker game, Harris sees his opportunity to better himself - he offers his entire life savings for a partnership in Reece's next drive including him joining the drive. Reece in desperation accepts. The next morning, when Harris shows up, Reece tries to renege, not wanting to burden himself with an inexperienced as a partner, but Harris holds him to their deal. As they travel to Vidal's ranch, the cowboy life on the trail is not what Harris had envisioned. Harris is upset when one of the hands is killed by a rattlesnake bite during some fooling around by two other hands. Reece, still upset about having Harris along, continues to treat him harshly, but Harris toughens up and Reece starts taking a liking to him. When they reach their destination, Harris is devastated to learn that Maria has been married off by her father to Don Manuel Arriega. When Arriega sees them together, he warns Harris to keep away. During a fiesta, Arriega performs a dangerous stunt, placing a ring on a bull's horn from his horse, and challenges the Americans to do the same. Harris takes up his challenge, but Reece intercedes to protect Harris from himself. Reece confronts the bull on foot so as not to endanger his horse. On the cattle drive back to Chicago, Maria's marriage eats away at Harris. He becomes as callous and hostile to others as Reece had previously been to him. At one point, Reece stampedes the herd in order to save Harris from a Comanche ambush while he is out alone rounding up strays. Reece is shot in the leg, and Harris takes over as trail boss while he recovers. Harris tells Reece that the 200 head of cattle that were lost are all coming out of Reece's share. Harris drives the men hard. Reece offers advice, but Harris refuses to listen. When one of the hands, a former US marshal, kills one of his friends while drinking together and then takes his own life, Harris callously orders the men back to work. Later Reece saves Harris's life after he foolishly enters a crowded cattle car on the train. Harris snaps out of it and suggests that the lost cattle be shared 50/50. At the end of the drive, they boisterously take over part of the hotel where Harris used to work, much to the surprise of his former boss.
