“Aman” the amazing-man
While staying at a hotel, John Aman and Zona Henderson rush to the aid of a woman who faints in the lobby. Although the woman insists that she is fine, Aman manages to read the telegram she is holding. It was informing her that someone destroyed the family oil well and killed her father in the process. Deciding to investigate this, Aman and Zona charter a course to Custer, Wyoming.
On the way they spot another oil well on fire. Landing to investigate, one of the local tells Aman that authorities suspect this is the work of foreigners. This is correct as it is the work of the Amazing-Man’s greatest foe, the Great Question. From his hideout in Tibet, he contacts his operatives in Wyoming to inform them that Aman has fallen for their trap.
The leader of the local gang then starts the next phase of their scheme by having the local deputy — who is on their side — to lure Aman into an ambush. Aman and Zona are lured to a nearby cabin but when the deputy abruptly leaves, Aman correctly deduces it is a trap. Picking up Zona, the Amazing-Man manages to run clear of the cabin just as the crooks set it to explode.
With this scheme having failed, the Great Question orders his minions to use the local Native American tribe to carry out the next part of their plan. By this time, Aman has captured the deputy and forces him to reveal the entire scheme. He then goes after two of the other crooks but they inadvertently kill themselves when one of them drops a stick of dynamite. While he is busy, a gang of Native Americans take Zona prisoner.
Aman is tipped off when a plane passes by and drops a note warning him that Zona will be killed if he does not stop interfering in the Great Question’s plans. Flying his own plane, Aman tracks down the other craft and forces it to land. He forces the pilot to tell him the location of gang’s hideout. There, the Amazing-Man tries to rescue Zona but is struck in the back of the head — one of his few weaknesses — and is knocked out. The gang leader then loads Zona onto a plane and tries to escape.
Meanwhile, the Amazing-Man wakes up and is briefly amnestic until he falls and strikes his head a second time. Searching the cabin for clues, Aman discovers that their other hideout is in the Rockies. Discovering that his plane has been sabotaged, the Amazing-Man uses a motorcycle to get to another airport an secure another plane. Flying over the enemy hideout, Aman leaps own in the form of the green mist and ambushes his enemies.
He quickly saves Zona, smashes the Great Question’s communication device and rounds up the crooks for the authorities.
Zona Henderson convinces Aman the Amazing-Man to go on a vacation cruise so they can finally have some time to relax. However, Aman only agrees to go on this cruise in order to investigate a series of strange murders that involve poison. He exposes the killer who has been using blow-darts to kill his victims.