Action Comics #245

In "The Shrinking Superman!", Lois finds herself caught in a twist of fate when she accidentally frees the villain Zak-Kul from the tiny city of Kandor, setting off a chain of events that traps Superman inside the jar of Krypton City. With Zak-Kul impersonating Superman and even marrying Lois, the real Man of Steel must use the last remnants of Illium-349 to shrink beyond the atomic level, slipping through the very structure of the jar to reclaim his identity and stop the impostor’s dangerous game.