The play, by Joseph Kesselring, is a farcical black comedy revolving around the Brewster family, descended from the Mayflower settlers but now composed of maniacs, most of them homicidal, including two spinster aunts who have taken to murdering lonely old men by poisoning them with a glass of home-made elderberry wine laced with arsenic, strychnine, and "just a pinch" of cyanide . The hero, Mortimer Brewster, is a drama critic who must deal with his crazy, murderous family and local police in Brooklyn, New York, as he debates whether to go through with his recent promise to marry the woman he loves, Elaine Harper, who lives next door and is the daughter of the local minister.