Conor, Abeke, Meilin, and Rollan race to stop an ancient enemy with the power to strip spirit animals from their partners, while one young hero faces the loss of a spirit companion.

When the world of Erdas faces a new threat, four young heroes and their spirit animals are determined to stop it as they embark on a journey that takes them deep underground and to the far corners of the world.

Captured by an evil sorcerer, I'm forced to become his apprentice and learn forbidden magic. Teetering on the edge between good and evil, I trade my soul for power. Allemar wants to control me, but little does he know the shifter he's caged-- is not easily tamed. My training draws me closer to Aspen, the forsaken prince, wanted for treason against the crown. My sisters have always feared him, but I can see the man beneath the cloak of hate. For I...

Continues the adventures of Conor, Abeke, Meilin, and Rollan and their spirit animals as they continue their efforts to protect Erdas from dark forces.