Meet Billie Upton Green and her very accidental diary - and don't you dare call her B.U.G! Billie has taken the new girl at school under her wing. She'll teach her the important stuff - Biscuit Laws, Mrs Patterson and of course where to sneakily eat a Jaffa Cake. She might even get invited to the event of the year (Billie's mums' are getting married). But then suspicion sets in. The new girl seems very close to Billie's best friend Layla. And she knows a lot about the big school heist - the theft of Mrs Robinson's purse. But, Billie is on to her. Well, as long as Patrick doesn't catch her eating biscuits first. Join Billie in this laugh-out-loud adventure!