When she returns to the manor, relations between the sisters deteriorate to the point where they start using their powers against each other. This results in the Power of Three being broken. They lose their powers and are now an easy target. Ironically Phoebe goes round to Cole' place is search of solace. Cole is at breaking point. Torn between killing Phoebe and his strong feelings for her, he sends her away.
A disgusted Andras has been watching all this. He possesses Cole in his Belthazor form and sets out to finish his work. The Charmed Ones reconcile just in time and get their power back. When Prue deflects Andras's blast back at him, it separates him from Belthazor who then kills him. Belthazor himself gets away, though he is wounded by Piper, leaving some of his flesh behind! Called before an angry and disappointed Triad, he promptly kills them all!