Even in the womb, Phoebe's (Alyssa Milano) baby is showing signs of demonic powers. Anxious to rule the Underworld, The Seer (Debbi Morgan) schemes to steal the baby and plant it in her own body. Meanwhile, the malevolent infant is slowly but surely taking over the rest of Phoebe's body, with the intention of killing Phoebe's half sister, Paige (Rose McGowan). Has the time come at last to enact the all-too-rare "Power of Three" spell? ~ Rovi