Alexander Luthor, Jr. (the son of Earth-Three's version of Luthor) returns to the DC Universe along with other survivors from Crisis on Infinite Earths as part of a scheme to replace it with a perfect Earth. He masquerades as the mainstream Lex Luthor and creates a new Secret Society of Super Villains. In response, the real Luthor takes on the identity of Mockingbird and forms the third incarnation of the Secret Six to counter the Society. The two have a confrontation during the main Infinite Crisis story and the mainstream Lex Luthor helps Earth's heroes locate young Alexander Jr. After Infinite Crisis ends, Luthor oversees Alexander's execution at the hands of the Joker in Crime Alley.