Debbi Morgan makes her first series appearance as The Seer, who foresees the death of The Source of All Evil (Peter Woodward) at the hands of the Charmed Ones. To prevent this, The Source breaks a centuries-old agreement between good and evil, unleashing an ancient vapor called the Hollow that has the capability of destroying the girls and their magic. Reformed demon Cole (Julian McMahon) wants to help the Charmed Ones in their efforts to stave off The Source, but Phoebe (Alyssa Milano) has a premonition that Cole's gallantry will destroy him as well! ~ Rovi