Even a demigoddess must have a weakness. On the run from the Coven she used to call home, Harley Merlin knows that Katherine's power and influence are spreading like a poison. And she has no doubt that Katherine will follow through with her promise to torture and kill her friends, one by one. Then Harley discovers that the key to her enemy's undoing might be hiding in a familiar place--her parents' Grimoire. With Finch, Wade, and Garrett by her side,...