Margaret Marshall is the chairman of the board of the cosmetic firm, Margaret's Cosmetics. Margaret, is a stunning woman in her late thirties, successful both with men and in business.
After meeting Darrin Stevens (Dick York) at his office, Margaret insists that he fly to Chicago that night to complete the quarter million dollar campaign he had planned for her company.
Darrin is in a pickle, since he had already planned to spend the evening celebrating his seven month wedding anniversary with Samantha (Elizabeth Montgomery). Fumbling out of the anniversary arrangements with Samantha, Darrin flies to Chicago, and meets Margaret, who has become quite interested in him, aboard her yacht, despite the fact that she knows he is married.
Meanwhile, Endora tells Samantha that Darrin will stray eventually simply because he's mortal.
While there, Darrin sees a stray Siamese cat, and feels it may be Samantha, egged on by her mother, Endora (Agnes Moorhead), to fly to Chicago to check on his activities. When Margaret leaves to slip into something more comfortable, Darrin is seen crawling around the room pleading his innocence to "Samantha".
Margaret returns wearing a slinky outfit consisting of a short skirt and fishnet stockings showing off her fabulous legs. She does this to prove that she should be the face of her advertising campaign, despite the fact that she is in her upper 30s. Margaret takes him in her arms and kisses him.
While Darrin evades Margaret's advances, a pelican arrives on the scene. Although both Margaret and Captain Kelly feel there is something strange in Darrin's reactions to the animals, Margaret, realizes Darrin is truly in love with his wife. She eventually gives up her pursuits, and accepts his advertising campaign.
Greeted by Samantha at home, Darrin is reassured that the cat he has brought with him is not his wife. However, when the pelican arrives, Darrin is uncertain whether it might not be Endora.
- Martha Hyer appeared as Tracy Richards in the 1966 episode "The Riches Woman" for the TV series "The Beverly Hillbillies".