While Darrin is away on business, Samantha fends off a magazine sales-man by twitching herself into a hag. Darrin phones Samantha to forward some papers. Later, Samantha twitches a cat back to Miss Parsons, who loves cats. Darrin's mother arrives while Cousin Serena is minding Tabitha. Resenting Mrs. Stephens' catty remarks about Samantha and her family, especially Uncle Arthur's sherry nipping, cousin Serena turns her into a cat. A large dog chases her up a tree and Miss Parsons rescues her. Learning what happened, Samantha starts trailing her. Samantha finally tracks her mother-in-law to Miss Parsons, who has about a dozen cats, all with bells on. The magazine salesman, now working on Miss Parsons, dashes off when he sees Samantha. Meanwhile, Serena entertains Darrin's father, who has come for his wife. Samantha, unable to pick out Mrs. Stephens, snaps her fingers, turning all the other cats into puppy dogs. Samantha takes the cat home and Serena changes her back. Later, Mrs. Stephens wonders how she got the bell around her neck. She decides she had too much of Uncle Arthur's sherry.