After a botched sales meeting and a run-in with Larry, Darrin is convinced that he's been hexed by Endora and retreats to his bedroom, utterly defeated. Enter prankish Uncle Arthur, who gives Darrin a lucky charm which will supposedly make him immune to witchcraft. Chances are that this is another of Arthur's practical jokes, but Darrin won't find that out for certain until it's too late. Written by Ed Jurist, "The No-Harm Charm" first aired on April 25, 1968. ~ Hal Erickson, Rovi