In the Fortress of Solitude, Superman, Cyborg and Atom make preparations to miniaturize Superman so he can visit the bottle city of Kandor. It is the only living remnant of Krypton left, so Superman is both reverent and boyishly excited to go. Atom reminds him that due to the simulation of Krypton's red sun, Superman will be without his powers.
Outside, however, Brainiac has approached and disabled a Superman robot, using it to gain access to the Fortress. His plan is to steal back Kandor and return it to its place in his collection of miniaturized cities.
Superman has only a moment to greet the city's chancellor and be introduced to the citizens of Kandor. They cheer for him, but they soon begin running and screaming as Brainiac's face appears beyond the glass. Superman fires up his jetpack to go stop the evil intelligence. Unfortunately without his powers he doesn't have the strength to dislodge the tech plug keeping the atmosphere in.
Brainiac, meanwhile, has shot a disintegration ray at Atom and disabled Cyborg. His companion bots have made short work of the Superman bots. He takes the bottle city and begins to head back to his ship.
Cyborg is pleased to discover Atom survived by miniaturizing before the ray could strike. But the bad news is that Cyborg's systems need time to reboot and come back online. Atom must go after Brainiac alone.
Brainiac's vehicle is making tracks across the ice only to be stopped when a Superman bot rips its turret off. This one has no head and is being flown like a spaceship by Atom. The tiny hero fights gamely but he's outnumbered and is only working with a damaged bot after all. The bottle city falls into the Arctic, beginning to freeze the city. But in the process the plug is knocked loose and Superman, still tiny, finishes the fight. He retrieves the bottle, restores the plug, and uses his heat vision to restore the climate.
