The town and surrounding ranches of Swiftwater are being terrorized by blackmailers who send their ransom notes and threats with ace of spades cards. Ted Ames, a young, happy-go-lucky Swiftwater rancher, is in love with Sandy McKenzie. Although she is in love with Ted, she is disappointed in his apparent laziness, as he has let his ranch go to shambles. Ted sells eleven horses so he can give Sandy a horse named "Apache," but she refuses the gift and breaks their engagement because of his extravagance. Disconsolate, Ted enters into a card game with brothers Len and Jake Stoddard, and loses not only "Apache," but his ranch as well. Jake accompanies Ted back to the ranch and is shot by a mysterious assailant. Ted leaves to try and capture the killer, but his disappearance leads Len to suspect him as murderer. Although there was no ace of spades when Ted left the body, Sandy informs Ted later that an ace was found with Jake's body, and that both she and rancher, Henry Kline, also have received one. Henry appears at his arranged meeting place to hand over ten thousand borrowed dollars to the blackmailers, who have threatened to kill him. He is joined by Ted. After handing over the money, they decide to work together to eradicate the thieves. Boyd Loomis tries to arrest Ted for Jake's murder, but Ted escapes on Boyd's horse and discovers Henry's money in the saddlebags. Ted returns the money to Henry, but is captured by Len and his gang, who are working for the blackmailers and who take him to their hideout. Ted escapes and, on the advice of an old prospector friend, heads to a basin where he suspects the gangsters are hiding. Ted finds the hideout and takes over the guard post. Sandy, who has been worriedly looking for Ted on her own, finds the basin and sends a note back to the sheriff on her horse, and then is captured. Sandy's horse and Ted's horse "Silver" return to her ranch, where the sheriff and ranch hands follow them back to the basin. Homer Truesdale, the banker, is revealed to be the head of the Black Aces gang. Ted rescues Sandy, and after a gunfight and other arrests, she reaffirms her faith in him.