Billy Kool was an ordinary boy until he was thrust into the life of an extreme sports TV celebrity. After skydiving, Nathan must honour his promise and retrieve the forty cricket balls from the monster's backyard. Will he survive his most extreme sport yet? After this, Billy, Sally and Nathan (if he makes it) will go mountain biking! At the end of the book, there is an extreme information section detailing the origins of mountain biking, a glossary and a description of the equipment used when mountain biking. Part of an 8-book series, the Billy Kool books are informative, empathetic and exciting; targeted to readers and reluctant readers alike ages 8-11 years.