A stolen Army tank is being used in bank robberies. Johnny, Hank and their Stutz Bearcat are hired to put a stop to things.
German troops, disguised as American soldiers, are raiding Mexican towns just across the border hoping to foment a war between the United States and Mexico.
Johnny and Hank try to stop a German assassin from killing a Mexican revolutionary who's raising money in the United States.
It's Johnny and Hank to the rescue when a small town is held hostage by a group of wannabe revolutionaries.
To revenge himself on a town, ex-convict Joe Bascom kidnaps a priest and demands that the town hang one of its citizens in exchange for the priest's release.
Johnny and Hank are hired by a newspaperwoman to rescue a group of Indians being held as slave labor at an archeological digging site by a gang of thieves seeking buried treasure.
Townspeople believe that nearby Indians are behind the sabotage of an oil well. Johnny and Hank arrive to get to the bottom of things before tensions can escalate.
Johnny and Hank are faced with the difficult task of breaking into a prison that's been taken over by a German military intelligence officer who's recruiting saboteurs.
Johnny and Hank clash with a ruthless rancher while searching for a friend who disappeared while on a top secret mission for the Army.
Johnny and Hank try to stop a saboteur who's been destroying medical supply shipment bound for the war in Europe.
A renegade Army colonel steals artillery in order to destroy an convoy of explosives bound for Great Britain and the Allied war effort.
Johnny and Hank call on their old friend, Mexican pilot Raoul Esteban, in order to stop a gang out to rob, loot, and pillage a mining town.
Hank and a gubernatorial candidate are being held by kidnappers and Johnny must rely on an ex-convict for help.