The Secret Circle: The Power
by L. J. Smith
The Secret Circle book 3: The Power United at last with Diana, the mistress of her coven, Cassie must first sacrifice her love for Adam to save the Secret Circle and the town of New Salem from the evil powers of the witch Faye. Threatened by the possibility of her destruction in a final battle between good and evil, Cassie must hope that her supernatural gifts are strong enough to obliterate the powers of evil. If victorious, Cassie will win more than she ever dreamed. But if she and Diana fail, the Power will go to those who seek only to destroy.