Jimmy, a young boy, idolizes famed train engineer Casey Jones and is devastated when his hero is killed in a train wreck. The boy grows up to be a railroad engineer, too, but one day the train he is piloting loses its brakes and wrecks. Jimmy tries to fix it but has to jump off at the last minute. Unfortunately, stories begin to circulate that he turned coward and jumped off the train first, letting it be destroyed rather than try to save it. He sets out to clear his name.
A mysterious criminal known as The Whispering Shadow commits crimes by means of a gang he controls by television and radio rays. Jack Norton, whose brother was murdered by The Whispering Shadow, suspects that the eerie Professor Strang - whose ghostly wax museum contains figures far too lifelike - may be involved in the crimes.
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.
Skinner and his gang are grabbing land from the ranchers. When they go after Kerry's ranch Ken stops them. Skinner frames Ken for rustling but the Sheriff is on Ken's side, and with the help of his brother Earl's Boy Scout troup they go after the gang.
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.
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.
When legendary hunter Bob Rainsford is shipwrecked on the perilous reefs surrounding a mysterious island, he finds himself the guest of the reclusive and eccentric Count Zaroff. While he is very gracious at first, Zaroff eventually forces Rainsford and two other shipwreck survivors, brother and sister Eve and Martin Towbridge, to participate in a sadistic game of cat and mouse in which they are the prey and he is the hunter.
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
Philip Wells and his wife Helen argue a lot about the attention that Philip thinks Helen and his best friend, Dave Burton, are giving each other, but they all sail off together on Philips yacht, until "Gorilla"Larsen and his motley crew show up, scuttle the yacht, and marital-strife is no longer the issue of the day.
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.
A young woman turns to Holmes for protection when she's menaced by an escaped killer seeking missing treasure. However, when the woman is kidnapped, Holmes and Watson must penetrate the city's criminal underworld to find her.
Prizefighter Jimmy Nolan, facing an opportunity to get a championship fight, is knocked out when he sustains what is apparently a permanent injury to his arm. From there, Nolan's path leads downhill. He is drawn into a romance with a nightclub entertainer, then is framed on a theft charge by a jealous suitor. After his prison term, Nolan makes a spectacular comeback in a fight which proves his courage and integrity, while disproving the fallacy about the old sports adage that "they never come back."
A young girl, who is about to receive a large inheritance, is abducted to an isolated sanitarium where a crazed doctor is performing strange experiments.
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.
Heading west, Ken and Bouncer end up at the Brooks ranch where Ken is to ride Tarzan in the big race. But both the Sheriff and Edmonds are after him and he must hide both himself and the horse until race time.
The Eagle uses sky writing to make threats against a corporation. Nathan Gregory owns a travelling fairground and is thought to be the Eagle. Craig McCoy is a pilot who goes looking for the Eagle when Gregory turns up missing.