World's Finest Comics #267

Direct

At the Pentagon, Superman and Batman meet generals and Challengers Ace and Prof. The Challengers' secret mission to find Dr. Brock failed and he was forced to create a \"gravity bomb\" that could disrupt gravity all over North America. Red and Rocky were captured. Despite repellent gravity waves, Batman, Prof., Superman, and Ace gain entry to the base holding Dr. Brock. Superman frees Rocky, who rips out the power to the bomb and sets everyone else free. Back at the Pentagon, Superman and Batman learn the Challengers are already off on another secret mission \"challenging the unknown.\"