As usual, Endora is angry with Darrin about something and, as she always does, she decides to use witchcraft to get her own back on the son-in-law whom she has always disliked. With the help of a conjured up warlock, she sets her sights on ruining Darrin's advertising career. The warlock comes across to Larry Tate as a superb campaign executive and Larry thinks that all of his ideas are fresh and wonderful. At the same time, he takes a great dislike to Darrin's work, a fact that makes Darrin so angry that he decides to quit the agency.
As usual, Agnes Moorehead steals the episode and makes it her own, much in the way that Marion Lorne used to do in her role as Aunt Clara.