A little investigating soon leads Buffy and the gang to the necromancer who originally killed the sorcerer, an immortal Russian sorceress named Yulia Dryanushkina, who can control vampires (which explains their reluctance to pass by her place of residence). When the crew pays Yulia a visit, she assures them that with Willow's assistance, she would be able to kill the sorcerer again should he be revived.
Neither Buffy nor Willow are particularly comfortable with aligning themselves with the necromancer, but they have no other choice when, twenty-four hours later, the vampires start behaving strangely . . . and half the senior class goes missing. -- From Amazon.com Product Description