As she and the Old One fight for Tyler 's soul , the Charmed Ones must defend the world from an army of monsters descending from the skies .
Prue enters into a final battle with Heremus .
As Prue and the Old One fight for Tyler 's soul , the Charmed Ones must defend the world from an army of monsters descending from the skies .
Prue enters into a final battle with Heremus .