The thirteenth instalment in the bestselling DORK DIARIES series, now with over 45 million books in print worldwide! OMG! Nikki's birthday party is going to be beyond awesome! Her BFFs are planning a SUPERcool pool party, with a cake, a DJ, and the perfect invitations. Organizing a big party for one hundred people is easy, right? UMMM wrong! When Mom says it's too expensive, soon it's looking like Nikki's dream party will be a total dorky disaster - cringe! Can Nikki and her BFFs come up with a plan to save the day, or will there be major birthday drama?!