Johnny Mack Brown was recruited by Chet Norman, the owner of a stagecoach line, to end the heist perpetrated by a mysterious knight who plays strange notes with a hiss…

A mysterious masked rider and his gang are murdering ranchers and robbing stages. Government Agent Johnny Mack Brown has been called in to help the Sheriff.

A marine biologist and a government agent investigate mysterious deaths and rumors of a sea monster in a secluded ocean cove, and find themselves involved with a marine biology professor…

Jungle Jim must protect rare pony-like animals whose glands produce a powerful narcotic. On the way, he fights a giant spider.

Two federal agents battle a gang that hijacks trucks carrying materials vital for the security of the country and sells them to foreign powers.

When three Texas Rangers try to investigate kidnapped Mexicans being used as forced labor in the mines of Silver Bullet, they are framed for murder by the town’s corrupt sheriff.

Before he was killed by Mark Foster’s men, Bud Lawton willed part ownership in his ranch to Hoppy and his two pals. When the three arrive they find a fake…