Season three of Charmed marks a number of significant changes in the lives of the "bewitched" Halliwell sisters of San Francisco, not least of which is the introduction to the series of Julian McMahon in the role of Assistant DA Cole Turner, with whom Phoebe Halliwell (Alyssa Milano) falls in love. Unfortunately, Cole is actually the demon Belthazor, whose earthly mission is to destroy Phoebe and her sisters for practicing "good" witchcraft. Ultimately, Cole also falls in love with Phoebe and balks at completing his mission, getting him into deep trouble with his demonic superiors, the Triad. Vanquishing his "bosses," Cole declares that he is purged of his evil ways...but he's just a bit premature in this declaration, as proven by later events. Meanwhile, guardian angel Leo Wyatt (Brian Krause), still in his "mortal" state, proposes to Piper Halliwell (Holly Marie Combs), and she accepts, armed with the foreknowledge that she is fated to be the mother of Leo's baby. As Piper and Leo exchange their vows, word has leaked out about the Halliwell girls' special powers, putting them in the uncomfortable position of being local celebrities. On a more tragic note, a deranged wannabe witch shoots and seriously wounds Piper. In desperation, Phoebe tells Cole (who has reverted to evil) that she will sacrifice herself and remain with him in the Underworld if only Piper's life is spared.