Emily, Trellis, and Vigo visit Algos Island, where they can access and enter lost memories. They're hoping to uncover the events of Trellis's mysterious childhood -- knowledge they can use against the Elf King. What they discover is a dark secret that changes everything. Meanwhile, the Voice of Emily's Amulet is getting stronger, and threatens to overtake her completely.

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.