 Evil high-priestess Dantalian, who was send by the Source, uses shape-shifting warlock Zile to trick Prue, in the shape of her lover Justin, into a kiss and black marriage that turn her evil, and it soon works on both her sisters- but she believes the Book of Shadows will grant her enough powers to turn on all other demons. Cole, who has moved heaven and earth to hide his survival from hell, is so eager to prove Phoebe his love that he advises her and even risks his safety spying on demon suspects. Now only Leo still plays by the rules of good...