Two friends quarrel over a found baby, starting a feud over water that is finally settled when the child grows up and develops a mining business.
Jeff Cameron (J. Farrell MacDonald) and Cash Holbrook (William Farnum) find a baby boy in a wagon at a deserted waterhole. They can't agree on a name, and Cash takes "Bill."
A generation later Jeff has not given water to Cash's cattle, as he and his daughter Mary Ellen (Helen Twelvetrees) prepare to defend it. Rance Brett (Clark Gable) asks Jeff for a job so he can get a horse. Cash brings his cattle to the waterhole, but his son Bill (William Boyd) drives them off to prevent a fight. Bill shows Cash tungsten ore that could be mined on Jeff's land, and he asks Cash to help him with money. Cash raised Bill and sent him to mining school; but he won't make up with Jeff and tells Bill to leave. Bill calls on a hostile Mary Ellen and Jeff. Bill explains about the ore and says both Jeff and Cash are wrong for hating. Jeff agrees to go in with Bill, because he found him. Mary Ellen apologizes to Bill, and Bill says she and Jeff will have money and that Cash is a kind man.
Men work the mine and bring in the first load. Mary Ellen goes to school in town with the wagons; but some of the wagons are taken. Tex is shot but manages to tell Bill it was Cash's men. Bill takes seven tons of ore into town in order to pay the bank. Mary Ellen was worried about Bill, and they schedule a wedding for four o'clock. Jeff learns that dynamite was stolen, and explosions cause the mine to cave in. He sends Rance to tell Bill the mine is out of business. Cash is blamed, but he recounts the story and says he didn't do it. Cash offers his bank account to Bill, and Bill gives half his share of the mine to Cash. Now Cash can water his cattle at Jeff's well. So Jeff rejects Bill for selling out to Cash. Bill hits Rance for causing trouble and forces him to confess to all the wrong-doing. Not having heard this, Cash and Jeff shoot at each other, both hitting Bill in between. In the final scene at four o'clock Bill tells Mary Ellen they will be late at the courthouse.
This story shows how the hostility of a western feud can go on for a long time until a young intermediary they both value can bring the opposed sides together. Best friends had become worst enemies because of their stubborn resentment. Fortunately the next generation had better attitudes.