After returning to her realm, Cassia continues to use the magic she'd discovered in Selene. Little did she know, that wasn't allowed and because of it, she's abducted by the king. Luckily, Prince Lochlan is still living in the castle pretending to be under the king's command. After Lochlan frees Cassia, they all need to flee Selene to escape the king and find allies elsewhere.

But in this new realm, all the inhabitants are afraid of the dark where a shadow is lurking, feeding upon them.

With nowhere else to go, they have to choose, either they face the king or this eternal shadow.