Tom Mix trades horses for cars. Tom Higgins meets Patricia O'Malley whose father is a car manufacturer. O'Malley is hoping to land a contract with a Japanese firm, if only his car wins the Los Angeles-Phoenix auto race. Hap enters, but O'Malley's driver, Luther McCabe causes the race to be lost. Higgins discovers that McCabe is in league with O'Malley's competition, so for the next race, in Fresno, he takes over when McCabe drops out and wins the race.

Young Kendall struggles for acceptance in the eyes of his wealthy father, who sees him only as a layabout.

Thinking he’s performing a good deed stagehand Droppington causes the breakup of the current show when he turns the full strength of the hose on what he supposes to be a fire in the theater. The fact of the matter is magician Mephisto was performing one of his tricks, hence the smoke.

Arling, ringmaster of a small wagon circus, abuses Polly and her seven children. Foy, a farmhand, sympathizes with her and she decides to quit her place as trapeze woman in the show and get other work. She sends her brood to the poorhouse, and Foy, ignorant of her flock, makes love to her and is accepted.

The will of T.W. Glutz provides that his bashful nephew, Hank, will inherit the entire estate if married by 2 P.M. of a certain date. Hank loves a girl who lives fifty miles away, but his uncle's executor, a lawyer, arranges a marriage with a somewhat antiquated home product. At 1 P.M. on the appointed day, Hank is sleeping off the effects of the night before. He wakens with a fever, a raging thirst, and an awful taste, when the lawyer enters and tells him the bride is waiting. "And my heart is fifty miles away," sadly muses Hank.

Cowhand Steve Ransom discovers that German spies are operating along Mexican border, relaying their radio messages into Mexico and thus on to Germany. The spies learn that Steve is a fugitive from American justice.

A young engineer, Tom Morley, is building a railroad through Imperial Valley. Tom's father also wants the job, and tries to persuade his son to give up the work, but Tom refuses. Tom falls for a society girl named Alice Hale, who marries him to bring prestige to her family. Initially, Alice plots against Tom, but Tom wins her over and they work together to defeat those who are plotting to destroy Tom's work.

Laura Bruce is married to John Bruce, police commissioner. She discovers her husband is enjoying a drunken revel with another woman, and vows she will obtain a divorce. After doing so she weds Paul Ramsey. His employer, Dick Turner, a libertine, offers his a responsible position in the west, and she faces a long separation. Ramsey later learns that Turner is interested in his wife and engages a man to protect her, who happens to be her former husband.

Henry Baird, a young newspaperman with a second-hand car but little money, decides to raffle off the car at a county picnic, so that he can take out his sweetheart, Mabel Darrow, the daughter of a wealthy businessman. However, as soon as Henry gets the money, his tailor demands that he pay off his debt. Also, youngsters set the car on fire before he can give to the winner, Joseph Plant, whose wife Evelyn was formerly Henry's sweetheart.

Lucy Bostil, daughter of a Colorado ranch owner, is led by a dog to his master, Lin Slone, who is exhausted from a struggle to capture a wild horse; she revives Lin and they christen the horse "Wildfire." The Bostils have entered Sage King in a race, but Lucy agrees to tame and train the wild horse, since Buckles, her favorite colt, has been stolen. When Joel Creech, a half-witted stable hand, is discharged, he becomes a tool of the Cordtses--who also have entered a horse (Buckles) in the race--in drugging Sage King. Lin and Lucy enter Wildfire under the Bostil colors, and she rides him to victory, When Cordts is disgraced and discovered to be a horse thief, he persuades Joel to abduct Lucy. Joel does so, but first he kills Cordts. Warned by his dog of Lucy's danger, Lin pursues and rescues the girl.