Blood Sisters: The Last Mage IV. The Last Mage, #4

Nearly two years following the conclusion of "Dawn of Night, " Carter Nash, the Last Mage, is now faced with an even greater challenge. While the love of his life, Sara Berkley, has gained the Power and become a Mage, new sources of the Power appear in the small town of McLain, Mississippi where he resides. One source of the Power remains hidden from him while a group of five high school girls become Blood Sisters and are controlled by the return of a different power that holds a grudge against the Mage.
He has to find both sources before they combine to destroy him.