Last Battle Of The Icemark

Plot Summary
Oskan and Thirrin thought their bad-seed daughter was gone for good -- burnt to a cinder and cast out onto the Spirit Plain. But banishment did not kill Medea: It made her stronger. Now, allied with Cronus, embodiment of all evil, the young sorceress is plotting revenge. Queen Thirrin is distracted by a new invader whose troops ride huge triceratops-like beasts into battle. But the warlock Oskan realizes the true threat to the kingdom is the demon army assembled by his daughter. To ensure the Icemark's eternal safety, he knows he must destroy her soul--even at the risk of his own. 

Trivia

 * Last Battle of the Icemark is the third and final book in the Icemark Chronicles.