Accompanying a beautiful, sexy client to Chicago, Darrin begins to act strangely when he suspects that her cat is actually Samantha in disguise.

Knowing that Darrin needs a new model for a campaign, Samantha turns a stray Siamese cat into an attractive woman named Ling Ling. Ling-Ling, who knows she's a cat brings those cat sensibilities to her human life, Wally starts to fall in love with her. Ling-Ling likes the attention she is receiving from Wally and wants to stay human. Samantha has to figure out how to tell Darrin the truth about Ling-Ling while she and Darrin try to persuade Wally that Ling-Ling is not the right woman for him.

The mayor, ignoring his constituents' request to have a traffic light installed at a busy intersection, needs some of Samantha's witchcraft to convince him otherwise.