Wonder Woman #31 (1948)

When a female scientist develops a chemical that will reduce things in size she refuses to allow it to be made into a weapon only to dissapear soon after. Wonder Woman and Steve Trevor investigate but are soon shrunk to microscopic size. They must find a way to return to their normal size and prevent the chemical from being turned into a weapon.  The Holliday girls visit the Neptunians only to learn that the men have regained control of Neptunia. They contact Wonder Woman who returns to Neptunia to battle Solo and prevent the destruction of the Earth.  Wonder Woman matches wits with a con-man who is masquerading as a 14th century wizard.