Twelve-year-old Rosemary, Princess of Glo-Kazin 136, learns to set her priorities and make difficult decisions that affect all worlds. When she composes a song for the Greatest of Trees, she has no idea how her song will be used. She finds herself overwhelmed by summer choices. Pressure and advice from parents and friends lead her close to panic. But when she sees plants dying, animals sick and hears the latest news from Glo-Kazin, her path becomes clear. With her friend, Dirklee, at her side she sets out to make things right. As she overcomes fear and impossible odds, her many adventures lead her to explore caves, the interior of the Greatest of Trees and the root systems of trees. She discovers how tree roots respond to threat and how they nurture each other. Rosemary attempts to save a librarian from a high branch, Princess Dastar from a cliff-face, save Great Bird's nest and the Great Tree from being cut down. As she defeats Professor Astrolabius and the Gorgons, she learns the effects of greed and dishonesty on the environment. Even though she thinks she has failed, she succeeds in fulfilling her promises and dreams. This gripping book of adventure, sci-fi and fantasy appeals to ages ten to fourteen and the young at heart of all ages.