World's Finest Comics #173

World's Finest Comics #173 (On Sale: December 12, 1967) has a Curt Swan and George Klein cover. This is the first issue of World's Finest Comics I purchased.

"The Jekyll-Hyde Heroes" is by Jim Shooter, Curt Swan and George Klein. Dr. Aaron is apprehended by the World's Finest Team for illegal human science experiments. When he gets out of jail, Dr. Aaron decides to take his revenge on Superman and Batman. First he learns which of their villains that they fear the most, then he uses psyche-distorter chemicals on them. The chemicals cause physical and psychological transformations which turn Batman and Superman into Two-Face and the space villain Kralik (being my first issue of World's Finest, I thought Kralik was a well-known and established Superman villain. Only later did I realize that Shooter had invented him for this one story and that he was never heard from again.).

As Two-Face and Kralik, the former heroes begin attacking Metropolis and each other. Robin deduces that the heroes have been turned into villains, but he is captured by Dr. Aaron before he can summon help. However, when Batman in his Two-Face guise decides to kidnap Dr. Aaron himself, the scientist is forced to drink his own chemicals and becomes the Composite Superman.

The back-up story is "The Super-Key to Fort Superman" reprinted from Action Comics #241 and created by Jerry Coleman, Wayne Boring and Stan Kaye. While visiting his Fortress of Solitude Superman discovers a message written on the wall which reveals that an intruder has penetrated the Fortress. Superman seals the entrance, but later learns that the intruder has returned.

Edited by Mort Weisinger.