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.
Rex
Rex King of the Wild Horses
Rin-Tin-Tin Jr.
Rinty
Bob Custer
John Sheldon
Lucile Browne
Alice Ingram
Ben Turpin
Henry
Edmund Cobb
Henchman Jim Luger
Richard Cramer
Frank Nolan
Lafe McKee
Charles Ingram [Chs. 1, 3, 12]
