Now that Lucy and Serena have found the diary, it's time to jump into their first adventure. Since the diary girls had a part, Serena decides it's the perfect opportunity to celebrate Lucy's twelfth birthday. Lucy isn't so sure. She knows only a few girls on the island, and some of them have been pretty rude. Will anyone come? Lucy's never had a birthday part with other kids before, so she decides to go for it. But in the midst of all their plans, one of the invitations comes back to her--with a threat to cancel the party. Lucy wonders if she made a big mistake. Should she cancel the party...or face the threat head on?