The Bat is a three-act play by Mary Roberts Rinehart and Avery Hopwood that was first produced by Lincoln Wagenhals and Collin Kemper in 1920. The story combines elements of mystery and comedy as Cornelia Van Gorder and guests spend a stormy night at her rented summer home, searching for stolen money they believe is hidden in the house, while they are stalked by a masked criminal known as "the Bat". The Bat's identity is revealed at the end of the final act.