Published Feb 1968 by DC.
Batman dresses as Two-Face in story.Pre-dates Batman #234
1st Silver Age appearance of Two-Face. Cover pencils by Curt Swan, inks by George Klein. The Jekyll-Hyde Heroes starring Superman and Batman, script by Jim Shooter, pencils by Curt Swan, inks by George Klein; Dr. Arron's Psyche-Distortor chemicals cause complete character reversal in Superman and Batman, turning them into their own worst enemies. The Super-Key to Fort Superman--Editors' Round Table: Superman, script by Jerry Coleman, pencils by Wayne Boring, inks by Stan Kaye; Someone has broken into Superman's Fortress of Solitude, so Superman searches the place for clues. Half-page ad with Neal Adams's pencils for the cover of Lois Lane 81. 36 Pages, Full Color. Cover price $0.12.