"Arsenic and Old Lace" is a dark comedy play written by Joseph Kesselring in 1939. The story revolves around two elderly sisters, Abby and Martha Brewster, who run a boarding house in Brooklyn. They are known for their kindness, but they have a sinister secret: they poison lonely old men to spare them from suffering. The plot thickens when their nephew, Mortimer Brewster, discovers their actions while preparing to marry his fiancée, Elaine. As Mortimer tries to manage his family's eccentricities and the chaos that ensues, the play explores themes of love, family, and the fine line between sanity and madness.