Notes:
Though Dick Sprang told Craig Delich he pencilled this cover, GCD art-spotters (Jim Van Dore, Craig Delich, Allen Ross, John Lang, Gene Reed, and Tony Rose) agree the Archives and Showcase Presents volumes correctly list Curt Swan for pencils. Letters credit from Todd Klein via his Klein Letters blog (18 September 2016, http://kleinletters.com/Blog/ira-schnapp-in-worlds-finest-comics-part-1/).
Character(s):
Superman [Clark Kent]; Batman [Bruce Wayne]; Robin [Dick Grayson]; Humpty Dumpty; Dr. King; Mousey [Jones]; Mother Goose; R. Melville; McKenna brothers and their nephew; "Foots" Moley
Synopsis:
Mystery Inc has set up a mystery for three high-paying clients so they can pretend to be Batman, Robin and Superman. A mix-up of dates causes the real superheroes to assume the parts that were to be played by the clients, and stop a real robbery in the process.