A seventeen-day blizzard seals off the valley, and a thrown-off balance in winter threatens the village's survival. Kælen and Sera follow the clues left by a hermit deep into the frozen underground vault, deciphering the precision regulating mechanisms left by the ancient people. Consulting old parchment scrolls, the two unlock the mysteries of a metal disc and silver rings, calibrating the cycle of the seasons again and again. When the foreign messenger Torin arrives with clues to a new ruin, they set out on a longer journey to uncover all the secrets of this ancient device that balances heaven and earth.