Seasons 4
4.01 "Charmed Again (Part 1)" - Mourning the death of Prue, Piper and Phoebe must now come to grips with the loss of their oldest sister, and the loss of the Power of Three. However, The Source discovers an unknown sister - the daughter of Patty and her whitelighter Sam, who had been kept hidden, Paige Matthew, the now-youngest Halliwell can restore the Power of Three and reunite the sisters' strength as witches.
4.02 "Charmed Again (Part 2)" - Furious that the Power of Three has been reconstituted, The Source knows that he has a 48-hour mythological time window to turn Paige from good to evil. Possessing the body of Paige's boyfriend, The Source brainwashes Paige into wanting to kill an innocent man.
4.03 "Hell Hath No Fury" - Paige takes the Book of Shadows into her work to cast spells which help her co-workers. Meanwhile, Piper, who is filled with anger over the death of Prue and the recent actions of Paige, is possessed by a member of a supernatural band of vigilantes known as the Furies.
4.04 "Enter the Demon" - "Witch Body is Which?" - While making a potion, Paige accidentally switches bodies with Phoebe. Meanwhile, when an apprentice ninja kills his master, the sisters must find a way to vanquish him, while learning to control their switched powers.
4.05 "Size Matters" - Piper, Phoebe and Paige are shrunk to a height of five inches when they walk into a trap set by a demon named Gamill.
4.06 "A Knight to Remember" - Paige accidentally summons a medieval knight, who believes Paige is the love of his life. However, the knight is under the influence of an evil sorceress.
4.07 "Brain Drain" - The Source sends Piper into a deep coma, where she perceives an alternate reality. Phoebe and Paige must find a way to return her to reality and save her from giving up her powers while she is delusional.
4.08 "Black As Cole" - Cole must face his true demonic nature when he is faced with another demon who is mistaken as the murderer of local witches who belong to the same coven. Meanwhile, Cole proposes to Phoebe, and Piper and Leo consider their future involving children.
4.09 "Muse to My Ears" - The Halliwell sisters must find a way to release Muses which have been abducted by a warlock who is attempting to build an evil faction in the absence of The Source.
4.10 "A Paige From the Past" - With Leo as her guide, Paige goes back in time to her teen years, in an attempt to resolve her feelings about the accident that killed her parents. Meanwhile, Piper must prevent ghosts, who have inhabited Phoebe's and Cole's bodies, from fulfilling their mission.
4.11 "Trial by Magic" - While Phoebe performs jury duty in a murder case, she is hit with a premonition about the real killer, and must convince the rest of the jury that the defendant is not guilty without exposing magic. Meanwhile, Piper, Paige and Leo try help Phoebe find the real murderer, but they stumble upon a gang of demons involved and they must solve the crime and keep Paige's friend out of danger before Phoebe gets thrown off the jury
4.12 "Lost and Bound" - Wanting to protect a ten-year-old orphaned boy who is a firestarter, Piper and Leo try to hunt down the demon before he can deliver the kid to The Source. Meanwhile, Phoebe is given Gram's wedding ring by Cole, but to their surprise the ring has been cursed to transform the wearer into a traditional 1950's suburban housewife.
4.13 "Charmed and Dangerous" - 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 sacrificing his life to save her from evil, but there may be more to the premonition that Phoebe just can't see.
4.14 "The Three Faces of Phoebe" - Phoebe develops a case of cold feet over marrying Cole and casts a spell which brings a young innocent Phoebe and an old cynical Phoebe to the Manor to help her make a decision. Cole now finds The Source is taking over his entire being. The Source's chief rival, who believes The Source is dead, is convinced by The Seer to kill The Charmed Ones in order to earn the allegiance of the entire underworld.
4.15 "Marry-Go-Round" - "Phoebe's Wedding" - As Phoebe prepares for her wedding day, she is completely unaware that the Source has taken over Cole's body, a plot that will likely ruin the big event. Meanwhile, when the Seer tells the Source that if he can marry Phoebe in the "dark way", it will insure that their future son will be the most powerful, evil being ever.
4.16 "The Fifth Halliwell" - Amongst newlyweds, Phoebe & Cole and already-married, Leo & Piper, Paige begins like a fifth-wheel but she continues her suspicions about Cole. Meanwhile, the Source plots to impregnate Phoebe with his evil spawn.
4.17 "Saving Private Leo" - When two ghosts from Leo's past return to seek revenge, Leo faces his demons by submitting, causing Piper's life to be threatened, leaving Paige to deal with the situation. Meanwhile, Cole tries to convince Phoebe they need a home of their own.
4.18 "Bite Me" - Hoping to defeat The Source and gain re-entry into the underworld, demonic bats bite Paige. If she in turn bites an innocent, she will become a Vampire forever. Cole tries to vanquish the Vampire Queen knowing that her death will kill all her vampires as well. Piper finally begins to suspect that Paige may have been right about Cole working with demons, but before she can say anything she learns that Phoebe is pregnant.
4.19 "We're Off to See the Wizard"- Phoebe tells Piper and Paige that she is pregnant, and that Cole is the father. Meanwhile, Piper and Paige team up with a wizard to stop the coronation of the new Source, unaware that it is Cole and Phoebe is soon to be his Queen of the Underworld.
4.20 "Long Live the Queen" - With the evil baby growing inside her, Phoebe is still torn between helping her sisters save innocents and taking on the duties of Cole's Queen. Cole pushes Phoebe to drink a tonic to strengthen the baby, knowing full well that this will also suppress her goodness. Piper, believing she has lost another sister to evil, becomes despondent and turns to drink to numb her pain. Paige comes up with a plan to get Phoebe to see the light and help her sisters vanquish Cole.
4.21 "Womb Raider" - The Seer enlists the help of a demon nobody has figured out how to vanquish to help her magically take the baby from Phoebe and become The Source in the process. The baby inside Phoebe starts to take over her body turning her into an evil creature of instinct. Piper and Paige must figure out ways to thwart The Seer's plans and prevent the baby from killing Phoebe.
4.22 - "Witch Way Now" - When the Angel of Destiny offers the sisters a chance to relinquish their powers and lead normal lives as a reward for vanquishing the Source of All Evil, their decision is put on the back burner, while they try and avoid an FBI agent who has them under surveillance and deal with Cole's calls for help, who is trapped in another realm, holding onto his love for Phoebe.
