The Slippery Slope is the tenth novel in the children's novel series A Series of Unfortunate Events by Lemony Snicket. It was illustrated by Brett Helquist and released on September 23, 2003. In the novel, Violet and Klaus Baudelaire make their way up the Mortmain Mountains to rescue their sister Sunny from Count Olaf and his troupe. They meet Quigley Quagmire, a character who they thought to be dead, and visit the headquarters of a mysterious organization called "V.F.D." They are reunited with Sunny and manage to escape from Olaf. The book has received positive reviews and been translated into several different languages.