Notes:
The on-sale date is from the publication date recorded in the Catalog of Copyright Entries, Third Series, Vol. 1, Part 2, Nos. 1&2, Periodicals, 1946-1947.
Synopsis:
With the war over, Spy Smasher retires. But Alan Armstrong discovers that crime hasn't taken a holiday when some thugs steal the plans for his Gyro-Sub that he plans to donate to the Smithsonian Institution.