An accident at a LuthorCorp lab creates two Lexs; Lionel turns back to the dark side.

What's up with Lex: LuthorCorp scientist Dr. Sinclair begins an experiment on a green meteor rock. Lex is there to watch and his excitement quickly turns to dread as things go horribly wrong. Dr. Sinclair is knocked down while Lex is hit by a ray the emanates from the rock. Lex is shaken but appears ok, he gets up and helps Sinclair to the hospital. After they leave another Lex gets up from the rubble... two Lexs!

What's up with Dr. Sinclair: Chloe and Clark show up to the hospital to see Lex. He's fine and even invites them to the lab to see what he was working on. Lex's openness catches Chloe off guard and she heads off to corroborate Lex's story with Sinclair while Clark heads to the Lab with Lex. In Sinclair's room Lex appears and tells Sinclair he thinks he was split in two at the lab. Sinclair is shocked but tells him if he had his notes he could rejoin the two. Lex then injects air into his iv, killing Sinclair and walks past Chloe as he exits the hospital.

What's up with Good Lex: Good Lex retrieves the notes from the lab and takes them home. He tells Lionel he'll help him with a fundraiser then begins to read the notes. While he's thumbing through them, Evil Lex sneaks up behind him and pistol whips him. When he wakes up, he's tied to a pillar and Evil Lex tells him he has to keep him here. He can't have another Lex running around. He'd kill him, but he's not sure what would happen.

What's up with Evil Lex: Evil Lex is unleashed on Smallville and raises hell. He tells Lana that if she won't be with him, he'll shut down the Talon and kick her out of her apartment. He then cancels his father's fundraiser and leaves a giant scar on Lionel's face by whipping him with a fencing epee.

What's up with Clark: Chloe discovers that there are two Lexs by hacking into the hospital security system and watching the surveillance video. Clark goes to talk to Lex and is fooled into thinking Evil Lex is Good Lex. He confides in him what Chloe has found and Evil Lex sets a trap, asking Clark to bring her to the lab.

How it ends up: When they arrive, Evil Lex convinces them to stay in a room while he goes to look for someone. When he leaves he makes a large piece of metal fall on the two. Clark shields Chloe and pushes the metal off. Chloe is unconscious and Evil Lex is stunned and flees the scene. Clark takes Chloe home and makes sure she's ok, when she leaves, he heads to the barn and runs into Evil Lex. The two verbally spare for a while. Evil Lex tells Clark he knows he's more than a mortal human. He offers a partnership; his brains and Clark's bronze. Clark refuses and Lex hits him with a kryptonite ring. Clark will join him or all those he cares about will suffer.

Just then, Clark's parents show up and Lex pulls out a gun. He shoots Jonathan in the knee and tells Clark to reconsider his offer. Clark gets his dad to the hospital and tells his parents he knows how to recombine the two Lexs. He super speeds to Lex's mansion and uses his super hearing to find Good Lex. He's able to free Good Lex, but Evil Lex is waiting. The three fight and Clark is left on the floor as the two Lexs battle. He uses his heat vision to make the kryptonite ring turn purple and the two Lexs are recombined.

Later, Lex says he doesn't remember a thing after being split in two. He apologizes to Lana and tries to do the same with Lionel. But Lionel says there's no need. Lex's attack was the wake up call he needed. Evil Lionel is back!