"After the tragic death of their father, Emily and Navin move with their mother to the home of her deceased great-grandfather, but the strange house proves to be dangerous. Before long, a sinister creature lures the kids' mom through a door in the basement. Em and Navin, desperate not to lose her, follow her into an underground world inhabited by demons, robots, and talking animals. Eventually, they enlist the help of a small mechanical rabbit named...

Emily, Navin and their crew of resistance fighters charter an airship and set off in search of the lost city of Cielis. there they hope to find held from the Guardian Council's powerful Stonekeepers. It's a mission that Alledia's survival depends on, and time is running out -- Emily's got to find Cielis before the Elf King finds her.

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. And when she seeks information from the Voice of her Amulet, she discovers that the Voice is much more sinister than she ever could...

Visiting an island that lets them access lost memories, Emily, Trellis, and Vigo try to uncover the events of Trellis's mysterious childhood, knowledge they can use against the Elf King, but they discover a dark secret that changes everything.