Plot summary
Dr. Arianna Carlin ( Emma Samms ), Lex Luthor's psychologist ex-wife arrives in Metropolis seeking revenge for his death and her targets are Lois and Superman. With the help of Dr. Heller ( Earl Boen ), a plastic surgeon who worked for Lex, she creates a duplicate of Lois, and kills Heller to cover it up. Carlin, using subliminal messaging in her books and media appearances to get the public to turn against Superman. The duplicate of Lois publicly accuses Superman of killing Lex and throws a tear gas in the newsroom of Daily Planet, to make everyone believe that Lois has gone insane as a result of stress from her failed wedding to Luthor.
At the same time, Carlin is hired by Perry on the Daily Planet as a therapist and uses her position to convince everyone that Lois has gone insane. Clark decides to help Lois investigate the truth even though he is not sure if he believes her when she says that she is fine. Eventually, they discover the true identity of Arianna as Lex's ex-wife and they reveal the truth but not before Arianna captures Lois and attempts to kill Superman using kryptonite -laced bullets, while making it look like Lois did it.
Lois takes the bullet out of Superman and he makes sure that Arianna and the Lois duplicate get arrested. Dr. Gretchen Kelly ( Denise Crosby ), who is taking care of Lex's body, previously stolen from the authorities, tells him that Arianna failed but he will always have her.
Credits
Adapted from Wikipedia contributors, Lois & Clark: The New Adventures of Superman season 2. HTML formatting and reference markers removed.