Season synopsis
Contains spoilers for this season and earlier seasons.
Season four confirms Prue’s death after the time-reversed Shax attack: Leo heals Piper but cannot save her elder sister. Another sister emerges: Paige Matthews, a social worker, is the daughter of Patty Halliwell and her Whitelighter Sam. Paige is wary of magic and her new family, but helps Piper and Phoebe defeat Shax and restore the Power of Three. As the sisters mourn Prue, they teach Paige to use the Book of Shadows and her witch-Whitelighter abilities, gradually making her part of the household and their work protecting innocents.
Cole loses his demonic powers and proposes to Phoebe, but later becomes possessed by the Source. They marry, and Phoebe eventually chooses him despite knowing he is the new Source. As Queen of the Underworld she still tries to protect innocents. Torn between her husband and her sisters, she finally helps vanquish him. The Seer transfers Phoebe’s supernatural pregnancy into herself to claim the throne; its power overwhelms her during the sisters’ resistance, destroying the Seer and the unborn evil being.
The Angel of Destiny offers the sisters normal lives without their powers. An FBI agent exploits their abilities, pretending to hunt a dangerous witch while actually targeting an innocent. They rescue his victim, and Cole returns from the demonic Wasteland with stolen powers to stop him killing Phoebe. The sisters decide to remain witches. The Angel then reveals Piper’s pregnancy, giving her and Leo the family news they had hoped for.