Prue, growing weary of her battles to save innocents and in fighting off the Angel of Death, is forced to turn her back on a dying soul, and must come to grips with her feelings towards fate and the death of her mother.

The Source breaks an age-old agreement between good and evil by stealing The Hollow, an ancient vapor which he uses to absorb Piper & Paige's powers. Meanwhile, Phoebe must allow Cole to help them, despite her having a premonition involving Cole sacrifici

Phoebe accepts her new role in Cole's life, but she still sets out to save an innocent after she has a premonition and even seeks her sisters' help in protecting the man. Meanwhile, Piper's heart doesn't seem to be in it as she prepares to defend her family against any new threats from the underworld.

When Grams comes to the manor for a Wiccan birthing ceremony, for Wyatt, the sisters find out that she has brought a memory from her past, a former lover who wants to kill the Charmed Ones and bring back the love they once shared. Meanwhile, Phoebe contemplates Jason's invitation, even though it will take her away from her family, and Paige casts a truth spell to figure out if Nate can accept her being a witch.

The Charmed Ones help out Leo's mentor, Gideon, when he wants to find out who cast the spell of darkness over a magic school and conjured the headless horseman who has been beheading the teachers. Meanwhile, Phoebe goes on a vision quest.

Gideon creates a portal that puts Chris and Leo in a mirrored world where evil prevails, and Phoebe and Paige travel to the parallel universe to rescue them. Meanwhile, Piper gives birth to baby Chris.

Agent Brody and Paige investigate when they discover that the demon Sarpedon is capturing innocents' guardian angels and using them to protect himself from the new power. Meanwhile, Piper and Phoebe encourage Leo to go on a vision quest to face his demons.

The sisters scramble to recover Pandora's Box when it falls into the hands of a shapeshifting demon who intends to open it and fill the world with all of its sorrows. Meanwhile, Paige's Whitelighter side rises to the surface, when she begins hearing calls from the Elders, and Leo and Piper clash over parenting issues - namely raising magical children.

Wyatt's school play brings out the competitive nature in Piper when her hand-sewn costume & parenting abilities are criticized by another mother. However things go from bad to worse, because this Stepford-like mother is actually a demon in disguise bent on kidnapping Wyatt in a plot to resurrect the Source. Meanwhile, Paige spies Dex with another woman, and despite Phoebe's objections, butts in.

During Chinese New Year, a demon attempts to steal a mystical wooden staff, that's protected by the Zodiacs and they enlist the aid of Piper. Meanwhile, Phoebe enjoys her new place by throwing a housewarming party that gets out of control; a monk teaches Billie how to use her power of projection to find her sister; Paige tries to get through to Henry about her magical abilities.

Forced to hide from Billie and Christy, the Charmed Ones find themselves stuck in the Underworld. Meanwhile, Leo appears to Piper and offers demonic approval; Coop searches for Phoebe; Billie & Christy resort to summoning the Hollow to stop the Charmed Ones and the Charmed Ones do the same.