Short Synopsis
The spirited spinster Miss Cornelia longs to play detective, and on a storm-swept night she gets her chance—and her turn at the vicious, elusive killer known as the Bat!

Full Synopsis
Miss Cornelia Van Gorder has left her New York City home for a vacation in an isolated country mansion with her beautiful young niece, neurotic maid, pompous butler, and a mysterious but genteel young man, only to find herself the victim of an elusive master criminal known as the Bat.

The spirited and headstrong spinster is not easily fazed, until one stormy night when she stumbles on a corpse. She musters all her nerves to play the vicious killer's deadly game and confront the Bat once and for all. The Bat, which draws from The Circular Staircase but adds some new plot complexities—namely, the villainous Bat—shows Mary Roberts Rinehart at the height of her career and is considered her greatest work.