S8, E5: Unaware that she is being watched, Billie jeopardises the Charmed Ones' new lives when she uses her powers to save an innocent. She is caught by Agent Murphy of Homeland Security, who has suspected all along that she and the `cousins' are involved in supernatural activities and that the Halliwell sisters are not dead. Meanwhile, Phoebe's overnight trip with Dex ends in marriage when they are put under a spell by Billie.