Sadie is a young puppy who loves splashing in the shallow waters of the small island and chasing crabs. Her days are filled with sunshine and eating nice big piles of garbage. But she's not part of a dog pack, she's alone, and the other dogs don't play with her. She'll soon encounter thrills and adventures that will truly test her courage. Will she always be an independent pup, on the outside of the packs? Or will she find her true place on the Isle of Lost Dogs?