Star Wars: The Clone Wars: Secret Missions is a book series by Ryder Windham. The series is based on The Clone Wars television series; however, it focuses on new characters and events. The books are published by Grosset & Dunlap, a division of the Penguin Group. The first book of the series, Breakout Squad, was released in September 2009. The second book, Curse of the Black Hole Pirates, was released the following year. The third, Duel at Shattered Rock, was released in 2011. And the fourth novel, announced in the third book's addendum, was called Guardians of the Chiss Key, and was released in 2012.