Rex, a wild stallion, and Rinty, a police dog, are pals. Their master , John Sheldon, is framed for murder, and Alice Ingram plans to race Rex for money to pay for John's legal defense. Meantime, Frank Nolan, who has falsely accused John, sets out to steal Rex for himself.

• Mascot Pictures
• Rex
• Rin-Tin-Tin Jr.
• Bob Custer
• Lucile Browne
• Ben Turpin
• Edmund Cobb
• Richard Cramer
• Lafe McKee