Brainiac, who shrank the city of Kandor and sealed it inside an unbreakable glass container decades ago, explores space for more cities, such as Metropolis, which only Superman can protect.
Reporters Clark Kent and Lois Lane cover the opening of a new museum in Metropolis when a blue whale skeleton comes to life due to the powers of Mr. Mxyzptik, who returns from the fifth dimension with troublesome tricks and magic that rivals the strength of Superman.
Bruce Wayne runs into Joe Chill, who murdered his parents years earlier, and recalls the story of his past, and development into Batman, as he chases down the crook.