Treasures of Dodrazeb: The Origin Key by S.D. McPhail

On a quest for vengeance against a criminal known as the Viper, Prince Rasteem becomes suspicious when his army easily conquers Dodrazeb. Princess Laneffri is desperate to expel the Persian invaders from her kingdom and will stop at nothing to protect its secrets–especially the Origin Key, a powerful, ancient device. Is Dodrazeb hiding the Viper or something even more dangerous? When Rasteem learns what the Origin Key can do, he must find a way to make the princess an ally to save both their kingdoms from annihilation.