Adventure Comics (1938 1st Series) #320 VG
Published May 1964 by DC.
Cover pencils by Curt Swan, inks by George Klein. Part I: Revenge of the Knave from Krypton!--Tales of the Legion of Super-Heroes, script by Jerry Siegel and Otto Binder (pgs. 4-9) [uncredited], pencils by John Forte (pgs. 1-3, 10) and George Papp (pgs. 4-9), inks by Sheldon Moldoff (pgs. 1-3, 10), George Papp (pgs. 4-9), and Al Plastino (Superboy and Clark Kent faces); Dev-Em arrives at Legion headquarters as a member of the Inter-Stellar Counter-Intelligence Corps on a mission to nab the elusive leader of the Cosmic Spy Legion, Morlock the Merciless, but loses the assignment to Superboy. Part II: The Treachery of Molock the Merciless!--Tales of the Legion of Super-Heroes, script by Jerry Siegel, pencils by John Forte, inks by Sheldon Moldoff and Al Plastino (Superboy/Clark Kent faces only); Superboy successfully completes Dev-Em's mission, with Proty II's help. Superboy's Switch in Time; Superboy is projected into his future, and is replaced by Superman, who must undo it. 36 pages, Full Color. Cover price $0.12.