Feeling invincible, Overlord Aart Xerxes has arrived at the Bion with an insatiable will for power. The ruthless overlord plans to use the newly awakened Omorfians to help him conquer his rival kingdom, Islaag. But members of his entourage, including his wife's brother Memphis, have formed a secret alliance against him. Will their plans to stop him work?

Meanwhile, in the wake of the overlord's arrival, fear and exhaustion from all the pain and loss overwhelm Leios and Emely as they scramble to join their comrades in Ignosi. There, the Omorfians must plan their next move: Will they return to the Sapien territory and fight or put their faith in their human allies, friends like Ferdi and the people of Islaag, to save them?

Knowing Overlord Aart's plans and not wanting any more bloodshed, Islaag's overlord and empress hope Ambroos-Aart's brother and the true overlord of Oever-will manage to stop the war before it starts. Wanting nothing more than a peaceful, simple life, Ambroos had been avoiding his duties, but knowing how evil his brother has become, he is willing to overthrow him. But will Ambroos be too late?

The Battle of Islaag is the thrilling and dramatic conclusion to the enthralling Omorfia Trilogy.