This is the sort of book that makes you believe in magic and love, in fact it make you believe that love is magic. You get this sense particularly at the ending.
Love and magic have had a hard time in the Protectorate where each year there is a sacrifice. The youngest baby is left out in a clearing in the woods presumably to satisfy the witch and keep her away. However, the only witch has been taking the babies each year to prevent them from being eaten by animals. She is a good witch who has been placing these babies in good homes, not knowing why they’ve been left.
When Luna is left out Xan keeps her as her granddaughter. She shares her house with a Swamp Monster named Glerk and a Perfectly Tiny Dragon, Fyrian. Xan recognizes at once that Luna has become filled with extraordinary magic from being accidentally fed by moonlight. As Luna becomes thirteen, her magic begins to reveal itself just as danger approaches. This book won the 2017 Newbery Award.