Emily survived the chaos of the Guardian Academy, but Max Griffin has stolen the Mother Stone. With it, the Elf King forges new Amulets that will give him the power to invade and destroy the nation of Windsor. Emily and her friends lead the soldiers of the Cielis Guard in a fight to stop him, but Max stands in their way. Emily seeks information from the Voice of her Amulet, but instead she discovers the Voice is much more sinister than she ever could have imagined.

After tragedy strikes their family, Emily and Navin move with their mother into the old, mysterious home of their great-grandfather. On their first night in the strange house, Emily and Navin's mom is kidnapped by a tentacled creature. Determined to rescue her, Emily and Navin are led into a world of robots, talking animals, flying ships, new friends... and enemies. Emily learns that she is a Stonekeeper and essential to the survival of this world, and that her incredible story is only just beginning.