Charmed

Season 8, Episode 9

Episode Title: Hulkus Pocus

Air Date: 2005-11-20

Overview:

When a demon escapes from custody, Agent Murphy enlists the Charmed Ones to help, where they learn a government created virus is spreading amongst magical beings, that causes them to "hulk out". Meanwhile, Billie becomes infected with the virus and it's up to the sisters to find an antidote.