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

Flora Hawks is in love with the overseer of Tarzan's African estate. After a search for a legendary city of diamonds, Tarzon races with his pet lion Jad-bal-ja to save Haws from being sacrificed to a lion-god.

Helen, informed of the danger which menaces an excursion train because another engine on the same track is running wild, mounts a motorcycle and speeds down the track to warn the passengers of their imminent peril. Nearing a river trestle under repair, she hurtles into the river; undaunted, she swims to the opposite bank and flags down...

A Cattlemen´s Association hires a detective (Bob Custer) to look into a series of cattle rustlings. To dismantle the plot, an undercover agent will be infiltrating the gang as a bandit.

Sinclair has a government lease on range land that is about to expire. George Ringold wants the land and hires Roberts and his men. But they turn out to be a gang of killers and trouble soon arises.