Mara, a young girl from a quiet valley village, longs for a world beyond the hills that surround her life. One day she discovers a shimmering veil on the ridge and steps through, finding herself in the wondrous Sky Garden, a city floating above the clouds. Guided first by the steward Serin and then by Kieran, a boy born within the city, Mara learns that the Sky Garden thrives on the power of a mysterious Heart Tree.
