Framed by Major Jenkins, Capt. Travers is kicked out of the Army. When Travers, now living with the Indians, is captured by Jenkins, the Indians attack the fort. With his men greatly outnumbered Colonel Burke realizes that Travers is their only chance.
John Mason returns to the Sally Ann mine to claim his half share. Janet Cater also returns although her father lost his half share to Joe Ryan. Ryan and his gang are also there to get the gold. A mysterious Phantom is also present. Mason's plan to expose Ryan as an outlaw and to force him to turn his share to Janet works. But when distracted by the Phantom, John is made a prisoner by the gang.
Steele gets into a fight with a ranch foreman, knocking the foreman out. The foreman was supposed to represent the ranch in a prize fight with a middleweight champion. Now Steele finds himself in the fight of his life.
Craig Larrigan's father and his partner own a large cattle ranch that is losing stock to rustlers. Craig, an easterner, heads west but in the disguise of a Mexican bandit. He is eventually thrown in jail with his identity still unknown. His cellmate is one of the rustlers and when they break out, the rustler takes him to the gang and Craig now has a chance to capture them all.
Montana and sidekick Pancho hire on at the Lopez rancho to fight Daggett and his outlaw gang. But Lopez's foreman Barnes is one of Daggett's men and he frames Montana for murder.
Karger is behind all the cattle rustling. After Tom Devlin catches his man Burke in the act, Burke hides evidence against Karger in his jail cell. Later when Tom is jailed he accidentally finds the evidence, but the Karger encited mob has jailed the Sheriff and is already on the loose.
Salomy Jane, a California mountain girl, is sought after by a number of men in the nearby small town of Redwood City. She is affected when two criminals are pursued by authorities: one for killing a hypocritical mayoral candidate, the other for robbing the stagecoach.
In the middle of the mountains around the Lötschental is a lonely village that is exposed to the forces of nature. A state of excitement arouses when an international mining company discover a gold vein and acquired mining rights.
Griffen and his two men have been caught after robbing a bank but the money has not been recovered. So the Chief sends his friend Tom to prison to become their friend and hopes he can learn where the loot is hidden.
Lovers David Lunch and Betty Summers are caught in the feud between their two families. When David kills the Summers son, he escapes to the West. He marries and when his boy is two he and his wife are killed by Indians who take the boy. Twenty years later the boy is now the Indian chief. Betty's daughter is nearby and the two are destined to meet.
O'Hara has been hired to lead a wagon train west. Instead he has led it off the trail to where it can be attacked by his Indian friends. But Tennessee Mathews is familiar with O'Hara's tactics and sends for the soldiers.
A cowboy saves his injured friend from a vigilante group, which believes that he is part of a bandit gang that attacked a wagon train. The cowboy sets out to find the bandit gang and clear his friend's name.
Kincade and Blake cause a mail plane carrying a payroll to make a forced landing in the desert. When they try to get the money, prospectors Ted and Si drive them away. With the pilot shot, Ted takes over as pilot figuring another attempt will be made and this time the Sheriff will be there.
While the original title, "Trailing the Killer" isn't a misnomer, it was a bit misleading since the "trailer" is a dog named Caesar (Caesar the Dog) and the killer is a mountain lion. But the makers also pointed out that Caesar "is the most intelligent dog actor since Rin-Tin-Tin" which probably lured a few Rin-Tin-Tin fans with a show-me attitude. Caesar prowls around the woods of the Northwest, dispatches a rattlesnake, visits his she-wolf mate and their pups, pauses to watch the dainty habits of a raccoon personally washing every morsel of food before eating it---and that raccoon had enough food to use up several minutes of running time---and then saves sheepherder Pierre (Francis McDonald)) from getting eaten by one mean mountain lion. Rin-Tin-Tin he ain't, but then who was?