Book the Eleventh: The Grim Grotto is the eleventh novel in the children's book series A Series of Unfortunate Events by Lemony Snicket. The book was released on Tuesday, September 21, 2004.

A Series of Unfortunate Events is a series of thirteen children's novels written by American author Daniel Handler under the pen name Lemony Snicket. The books follow the turbulent lives of orphaned siblings Violet, Klaus, and Sunny Baudelaire. After their parents' death in a fire, the children are placed in the custody of a murderous villain, Count Olaf, who attempts to steal their inheritance and causes numerous disasters with the help of his accomplices as the children attempt to flee. As the plot progresses, the Baudelaires gradually confront further mysteries surrounding their family and deep conspiracies involving a secret society, which also involves Olaf and Snicket, the author's own fictional self-insert.