Thirteen-year-old Anna Wells loves three things: Pony Club, her friends, and her pony, Polly Pocket. But when her mom rescues a severely starved pony abandoned on Beauty Island, Anna's world shifts. As her five-year-old sister forms a magical bond with the recovering pony, Anna's "overly developed justice muscle" goes to work. She and her best friends form the Animal Justice Club, determined to track down the people responsible for the abuse. 

But when all clues lead back to the Gordon family, Anna is convicted. Mrs. Gordon teaches the Pony Club lessons and Zane is a friend. 

How can they be mixed up in Dusty's past?