A Rin-Tin-Tin serial presented in 12 episodes. The mysterious Wolf Man is terrorizing settlers in a western town. With the help of Rinty, young Jimmy Carter unmasks the Wolf Man and foils his evil plot.

Nat Cutler, known as Hawkeye, is a fur trader. With his faithful Indian companion Chingachgook, the last of the Mohican tribe, he fights to protect settlers against the raiding Huron Indians.

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.

A prospector is murdered by The Cactus Kid and his gang, who hope to find the murdered man's goldmine. The miner's dog, Rin-Tin-Tin, recognizes the killers, who thereafter seek to use the dog to locate the lost mine. With the help of a government agent and a young girl, Rinty saves the mine and brings the bad guys to justice.

A mysterious master criminal known as The Voice plots with his gang to sabotage the Milesburg Oil Company, but the rightful heir has a secret army of her own to protect her rights.

Railroad detective Matt Clark roams the west, tracking down outlaws and bandits who are preying on the railroad.