Published Jul 1969 by DC.
Cover pencils by Curt Swan, inks by Neal Adams. Superman's Secret Past!, script by Leo Dorfman, pencils by Curt Swan, inks by Jack Abel; Could Superman be a two-timing super-deadbeat?. The World of Mr. Mxyzptlk!, script by Jerry Siegel, art by Al Plastino; After yet another round of pranks from Mr. Mxyzptlk, Superman travels to the fifth dimensional world where Mxyzptlk lives to perform pranks on him. This first 15c cover-priced issue contains a half-page letter from the editors explaining why DC increased the cover price of their comics from 12c to 15c. 36 pgs. $0.15. Cover price $0.15.