This serial sees Captain America, whose really District Attorney Grant Gardner, trying to thwart the evil plans of the Scarab, who is really museum curator Dr. Cyrus Maldor -- especially regarding his attempts to acquire the "Dynamic Vibrator" and "Electronic Firebolt," both devices that could be used as super-weapons.
The character drastically differs from his comic book counterpart, who was a frail soldier named Steve Rogers who underwent a super soldier experiment to enhance his physiology to the peak of human perfection. These elements are completely omitted and the character's identity was changed to District Attorney Grant Gardner.