On sale date from the publication date found at the Catalog of Copyright Entries, Part 2, Periodicals, New Series, Volume 35, January-December 1940, Numbers 1-4. Class B periodical. Copyright number B 441668.
Stardust, the scientific marvel whose vast interplanetary knowledge has given him greater powers than anybody else, has learned through his scopes that a mad giant experimenter, who dwells in the Gobi desert, is planning to destroy the world.