Lex reminds the press that because of the city's financial problems many museums have been forced to close "which is why the Lex Luthor Museum of Natural History is such a boom to the city's populace."
Moments before he gives them a guided tour before tomorrow's grand opening to the public, Superman comes limping out of the museum. He had heard, through his super-hearing, crooks inside trying to steal gems. It turned out one of those "rocks" was kryptonite. Later, Luthor, with his surveillance cameras, puts two-and-two together and is thrilled find out what kryptonite is, and that he has it. Later, he has a big goon pull a heist just to bring Superman to him and expose him to the deadly substance.
What happens afterward is so-so, nothing quite as dramatic as I expected to see. This whole episode is okay, but nothing that memorable except for Luthor's discovery, which he hopes to use as leverage against the Man Of Steel interfering with his crime efforts. Superman vows he won't be controlled and while he flies away, Luthor mutters, "Well, I guess I'll have to kill you."
Obnoxious Lois, meanwhile, thanks to a mole she has inside Luthor's complex, gets a piece of kryptonite and a scientist examines it and subsequently explains to both her and Superman what the substance is and why it hurts our hero...and that lead will protect Superman from it.
The best part of the episode is the final 3-4 minutes when Luthor traps both Superman and Lois Lane inside with a huge chuck of deadly rock and a giant mechanical dinosaur ready to devour the two.
