Not being successful in his suit for the hand of Helen Sawyer, and to show the father of the young lady that he is made of the same material as he is, John Thorpe, a wealthy New Yorker, leaves for the west, but without any predetermined destination. While traveling, however, he meets an old man called Uncle Billy, and upon this man's advice, Thorpe purchases a ranch in Buffalo, Wyo. Not long afterwards, the homesteaders are accused by the large cattle owners of stealing their cattle, and they give Tom Horn, commonly known as "The Killer," a list of those they desire to get rid of. Thorpe's name heads the list, but The Killer finds that Thorpe is his match and is thrown down. For this Thorpe wins the admiration of Cora Sands, the sweetheart of The Killer. As they are walking along the road, they are seen by Helen and her father, he having been summoned there to look after his ranch near Buffalo. Upon the suggestion of Sawyer, the large cattle owners formulate a plan to annihilate the homesteaders, and The Killer goes to Buffalo to get help and warns Cora Sands that he is going to kill Thorpe. Acting upon his threat Cora goes to advise Thorpe of his impending death, but finds that he had left. Fearing for his safety, she dresses as a boy and follows him. She is mistaken for Thorpe by The Killer and is shot. In the melee between the homesteaders and the bad men, Thorpe is wounded. He manages to reach Sawyer's house, where he is rescued from the clutches of The Killer by the timely arrival of the troops. Later, realizing that she does really care for Thorpe, Helen gains her father's consent to be his wife.