Bad Bargain (Buffy the Vampire Slayer)

A fundraising sale at Sunnydale High gets out of control when shoppers suddenly begin to be bewitched by their purchases. After the school is quarantined in hopes it will contain the creepy outbreak, Giles discovers that the items from the sale, which had been stored in the school basement, have been infested with a sort of demonic vermin that escaped from the Hellmouth directly below the school. Buffy and her gang must fight them off - or risk these strange creatures helping far worse things escape from the Hellmouth, bringing death and destruction in their wake...