Superboy Season 3 Episode 5

Roads Not Taken (1)

Luthor steps into an interdimensional portal created by a Dr. Winger and is whisked away to an alternate earth. Darla kidnaps Lana in order to lure Superboy to the lab where Luthor vanished. She tells Superboy that if he doesn't go through the portal to save Lex, Lana will die. Naturally, he goes through and is transported to an alternate earth where his alternate self killed Luthor's alternate years ago. Now the world is in chaos. Lana is homeless, everyone hates Superboy, and ""our"" Luthor, claiming to be that world's Luthor resurrected, is quickly taking over. Superboy finds Luthor, but is held at bay by kryptonite. He travels to the Bureau for extra-normal Matters and there encounters his other self, a Superboy who wears leather and dark glasses and just doesn't care anymore. He explains how he killed Luthor in a fit of rage by cutting him in two with heat vision. After the discussion is over, the Superboy of earth-1 heads to Dr. Winger's lab looking for a way back home.