Unicorn Academy #9 - Matilda & Pearl

Matilda loves to have fun. She's not too worried that her unicorn, Pearl, hasn't found her magic yet. She also loves her friends at Unicorn Academy--even when they get annoyed at her for being disorganized. But there's a problem so big that even Matilda can't ignore it. On a camping trip, she and Pearl see someone hurting the oldest tree on Unicorn Island. Can Matilda and Pearl find out who it is, and save the tree?