The Marshal sends John Weston to a rodeo to see if he can find out who is killing the rodeo riders who are about to win the prize money. Barton has organized the rodeo and plans to leave with all the prize money put up by the townspeople. When it appears that Weston will beat Barton's rider, he has his men prepare the same fate for him that befell the other riders.
A crazed scientist needs primates to conduct experiments to prove his own theory of evolution, so he organizes an expedition into the jungles of Borneo to capture the animals he needs.
When attacked by two dogs, Joe Gilmore leaves them on the desert to die. Later one of the dogs saves John Blake from drowning. Men arrive claiming the dog is killing their chickens. They want to kill the dog but John convinces them the dog's fate should be determined by a trial.
Easter, a soldier of fortune and gunrunner, leaves his family behind escaping from the authorities and an American detective named Mason. His globe hopping escape leads him finally to South America, where he is hired to organize a band of revolutionaries, unaware that they plan to eliminate him when his job is done.
A young lawyer is elected mayor of the city and promises to rid it of the corruption it's famous for. The problem is that most of the corruption he's vowed to eliminate is caused by the crooked political machine that helped elect him.
When Mark 'High Gear' Sherrod looses his nerve, the race car driver takes a job driving a taxi, but when he befriends a cute reporter and the young handicapped son of a deceased driver, he attempts to return to the track.
In this mythical fantasy, the evil queen of Atlantis lives in a magnificent palace, the halls of which are filled with the mummified remains of former lovers.
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?
Cowboy is hired by an archaeologist to help find "Hidden Valley", where an Indian gold treasure is supposed to be buried. Just when he finds it, the archaeologist is killed, and the cowboy his charged with his murder.
Steve Drexel voluntarily strands himself on a deserted island on a bet. He intends to re-create civilization and carves a miniature city of 52nd Street and Park Avenue out of the jungle. Drexel is befriended by his dog, a native monkey, and a wild goat that is captured in one of his traps. He attempts to cultivate a native as his Man Friday from Robinson Crusoe, but fails as the native escape.
When a young South Seas sailor falls overboard, the beautiful daughter of a Polynesian king dives in and saves his life. Thus begins the romance of Johnny and Luana. Though Luana is promised to another man, Johnny whisks her away, and for a brief time the lovers live very happily together. But, when a local volcano threatens their lives, Luana knows that she must sacrifice herself to the volcanic gods in order to save her island.
The Wrecker wrecks trains on the L & R Railroad. One of his victims is Larry Baker's father. Baker wants to find the evildoer, among a host of suspects, but it will be difficult since the Wrecker can disguise himself to look like almost anyone
Antinea, the Queen of Atlantis, rules her secret kingdom hidden beneath the Sahara Desert. One day two lost explorers stumble into her kingdom, and soon realize that they haven't really been saved-- Antinea has a habit of taking men as lovers, then when she's done with them, she kills them and keeps them mummified.
Natty Bumppo, known as Hawk-Eye, is a frontiersman in the American wilderness. Together with his Indian friends Chingachgook and Uncas, he fights battles against nefarious white soldiers as well as the vicious Indian Magua and his cohorts.
Canadian Mountie Mason is sent south of the border to look for a horse thief with only a watch chain for evidence. He befriends young Andy and when Calhoun hits Andy, Mason and Calhoun fight. In the scuffle Calhoun's watch with the missing chain is dislodged. Mason then sets out to bring in Calhoun and his gang.
Jim Gray is looking for the gang leader known as the General. When Neil Denham is murdered, Jim assumes his identity. He and his pal Squint Saunders then try to join the gang. But they get captured and Jim is told he can join up only if he kills his friend.