A boy named Auggie lives on an island at the top of world where he cares for animals in the Fabled Stables, a home for unusual and magical creatures. When the stable rearranges itself, opening up a stall for a new creature named Willa, Auggie knows he must venture into it. The stall leads him to a swamp where a creature called a wisp is trying to escape captors that want it to lead them to treasure.