Clark witnesses the kidnapping of Professor Craig Lipcott, a famous nuclear scientist. As Superboy, he follows the kidnappers to a rooftop and sees them enter a strange ship just before he is attacked by a powerful ray that leaves him disoriented.

An anonymous letter leads Superboy to Darla's hideout, where she has Lana locked in a meatlocker. She's holding Lana to blackmail Superboy, so he'll bring Luthor back through a portal (created by Dr. Winger) that took him to an alternate world. This alternate world is dark, and chaos has erupted as a result of Luthor's murder by an alternate Superboy. As Superboy tries to return Luthor, he and an alternate Dr. Winger attack him with kryptonite.

Lex Luthor has a plan to destroy the world's population with a series of dirty bombs, but first he must get rid of Superboy.