The Charmed Ones greatest enemy is finally bringing the fight to them. The Source of all Evil is breaking a pact made between good and evil and unleashing a power that he cannot even control. He is using the Hollow, an all-consuming being the devours all magical powers both good and evil...
Piper, Phoebe, and Paige have to find a way to stop both the Source and the Hollow before the world is plunged into a never-ending cycle of darkness and misery.
After amazing fighting and strategizing the Charmed Ones vanquish the Source, and with the help of the Seer, banish the Hollow. However, this leaves a void on the side of evil...Who will rise and fill it?
This is a great episode and it finally shows the end of the Source, and Prue is fully avenged.