Justice League Crisis on Two Earths is an original directtovideo animated superhero film released on February 23, 2010. It is based on the abandoned directtovideo feature, Justice League Worlds Collide, which was intended as a bridge between the thenconcluding Justice League animated television series and its then forthcoming sequel series Justice League Unlimited. Crisis on Two Earths was reworked from the Worlds Collide script to remove references to the TV series continuity.
In an alternate universe where evil usually triumphs over good and where the roles of the heroes and villains are reversed from their counterparts in the mainstream DC Universe, heroic analogues of Lex Luthor and the Joker called the Jester are attempting to steal a device, the Quantum Trigger, from the headquarters of the Crime Syndicate. The pair trip an alarm but manage to secure the device. The Jester sacrifices himself to allow Luthor to escape and kills Jedd Jarkus and Angelique alternate versions of Martian Manhunter and Hawkgirl respectively with a radioactive bomb. Luthor is confronted by the remaining Syndicate members Ultraman, Superwoman, Power Ring, Johnny Quick and Owlman but escapes to the Earth of the heroic Justice League by activating a dimensional travel device.Luthor locates a police station and is mistaken for the evil Luthor where he ends up stripsearched. The Justice League is summoned and Supermans xray vision confirms Luthors reversed organs indicate that he is from a parallel Earth and that the evil Luthor is still incarcerated at Strykers Island. The Justice League take the alternate Luthor to the Watchtower, where they learn of the Syndicate threat. As the Justice League debates the matter, Luthor hides the Quantum Trigger on the satellite. With the exception of Batman, the rest of the Justice League Superman, Wonder Woman, Green Lantern, Flash and Martian Manhunter travel to Luthors Earth. ........
Source: Wikipedia