In the mountain town of Bracken Hollow, the great clock tower has always kept perfect time. Its twelve tolls at midnight mark the steady rhythm of life, until one summer night when a thirteenth chime shakes the village awake. For siblings Mara and Finn, and their friend Elira, the strange bell is the beginning of a journey into the tower itself a place of vast gears, shifting forests of brass, and rivers made of flowing sand.
