Sixteen-year-old Eileen Adderson has spent her whole life in the trees. She lives in a treetop community meant to keep her and the other villagers safe from the phantom who resides in the forest below. For hundreds of years, he has killed the occasional wanderer, kidnapped children and teenagers, and filled the people with dread. No one has any clue where the children have gone; they only know that the phantom, Alastrus, took them. Nobody touches the ground if they can help it, but Eileen has no choice. She has been assigned to a team of Water Carriers who will venture deep into the forest to supply the village with water. As she walks on solid ground for the first time in her life, she can only wonder if she will meet Alastrus... and what will happen if she does.