Captain Marvel fights a masked criminal mastermind called the Scorpion, who is determined to gain control of an ancient weapon.

It is made in the form of a large metallic scorpion with adjustable legs, tail, and removable lenses that must be properly aligned in order to activate its powerful ray.

This allows young radio broadcaster and expedition member Billy Batson, who obeyed the warning on the crypt's seal not to enter, to be chosen by the ancient wizard Shazam.

Upon its destruction, Captain Marvel is instantly transformed back into Billy Batson forever, the danger from the device's curse having now been eliminated.

Paramount Pictures successfully tied up all the character's theatrical exhibition rights for its series of color Superman cartoons, produced for them by Fleischer Studios, which was awarded the license by the publisher.

[3] The license that Action Comics provided gave Paramount exclusive use and prevented other film companies from using the Superman character, even in a non-animated production.

[3] Undaunted, Republic's completed script was reworked with various changes; it now had an original masked hero, the Copperhead, standing in for Superman, subsequently becoming the Mysterious Doctor Satan serial.

Writing in his autobiography of the period, William Witney revealed that in his court deposition he had claimed that both Superman and Captain Marvel were derivatives of Popeye.

In the 1970s the dormant Captain Marvel family of characters was licensed and revived by DC Comics,[7] which they ultimately wound up purchasing, adding a final chapter to the Fawcett/DC saga.

[8] At the time, Tyler was a weightlifting champion and the serial costume matched Captain Marvel's original comic book appearance, right down to his being slender.

[9] Due to his convincing performance in King of the Royal Mounted, actor Robert Strange (as John Malcolm) was the obvious choice to be the identity of the Scorpion, but by the end of the serial he was just a diversion and not actually the villain.

[10] Republic's flying effects, under the direction of Howard and Theodore Lydecker, were performed using a dummy that was slightly larger than life (at 7 feet tall) and made of paper mâché so that it weighed only 15 lbs.

[9] The flying pose used for the dummy (arms outstretched and back arched) was based upon a Captain Marvel drawing by comics artist Mac Raboy.

Ironically, the decision to use cartoon animation for Superman's flying is puzzling, since these scenes took longer to make and cost more than a mechanical effect as Republic used.

One of Captain Marvel's tunics later appeared as the costume of a member of the Kryptonian science counsel in the first episode of The Adventures of Superman television series, filmed in 1951.

[1] The serial was re-released on April 15, 1953, under the title Return of Captain Marvel, between the first runs of Jungle Drums of Africa and Canadian Mounties vs. Atomic Invaders.

[1] Due to the superhero nostalgia craze in the U. S. during the spring of 1966, resulting from the hit Batman television series, the serial was quickly re-released again, this time as a complete, nearly four-hour-long feature film.

Kino International released the serial on Blu-ray on September 19, 2017; it contains a commentary track provided by film historians Jerry Beck, Chris Eberle, Shane Kelly, Boyd Magers, Leonard Maltin, Adam Murdough, Constantine Nasr, Donnie Waddell, Tom Weaver, and J.D.

The book is notable for reusing several characters from the serial and for being Otto Binder's first writing assignment at Fawcett; he went on to be a prolific comics writer for the company.