At the Pentagon, Superman and Batman meet generals and Challengers Ace and Prof. The Challs' secret mission to find Dr. Brock failed. He was forced to create a "gravity bomb" that could disrupt gravity all over North America while Red and Rocky were captured. Arriving in the Andes, Batman and Prof swim through tunnels. Superman and Ace fly around the hovering bomb, but are repelled by gravity waves. Superman super-makes an "energy attractor" to weaken the field and gain entry. He finds Rocky bound. Batman laser-torches inside tand finds Red. They climb acrobatically, then fiddle electronics to scuttle the Andes base. Superman gets pinned to a magnetic field. As Ace flies overhead, Superman signals by heat vision/Morse code, then bounces a flash to sever Rocky's bonds. Rocky rips out the power and Superman is free. Back at the Pentagon, Superman and Batman learn the Challs are already off on another secret mission "challenging the unknown."