Christy attempts to convince Billie that the Charmed Ones only use their powers for their own personal gain rather than to support the greater good; however, Billie expresses doubts about whether or not it is really their destiny to stop the Charmed Ones. Billie agrees with Christy's plans to kill the Halliwells after exploring the sisters' dreams and believing their "inner-truths" were driven by selfish desires. After turning the magical community against the Halliwells, Billie and Christy engage in the ultimate battle with the sisters, which destroys the Halliwell Manor and kills Christy, Phoebe, and Paige. Billie uses her projection power to travel back in time to save Christy, and discovers that she knowingly working with the Triad. She questions Christy's morality, and reunites with the Halliwell sisters to help them defeat the Triad. Christy and Dumain steal the cupid Coop's (Victor Webster) ring to travel back in time to warn the Triad about the outcome of the ultimate battle. Billie helps the sisters project back in time to vanquish the Triad and the past and present versions of Dumain. Billie unsuccessfully attempts to convince Christy to come back home with her. Christy refuses and throws a fireball at Billie and the Halliwell sisters; Billie telekinetically deflects it back at her and kills her.