Piper and Phoebe struggle with the loss of their sister, and also losing the Power Of Three along with her. Just when things are looking bleakest, a new half-sister named Paige is found, that could reignite the sisters powers. That is, if The Source doesn't find her first.
Piper and Phoebe race against time to find their half-sister Paige and complete the new Charmed Ones. The Source has a two-day window in which to bring her over the dark side, and his temptations are many.
Songs: Lily Frost -- Who Am I
New to the world of witches, Paige has trouble controlling her abilities, and also uses The Book Of Shadows' magic for personal gain. Meanwhile, an emotionally distraught Piper is easy picking for a band of female demon vigilantes known as The Furies, who are looking for new recruits.
Songs: Lily Frost -- Who Am I
Paige makes a major mistake while mixing potion, and inadvertently switches bodies with Phoebe. That isn't the sisters only problem though, as a Zen Master's talented disciple has gone rogue and opened a portal between our world and another.
Phoebe and Piper don't take Paige's bad feelings about a creepy house seriously, and Phoebe ends up shrunk to the size of a doll by the demon who resides there. When Paige and Piper also end up in his collection, the three have to find a way out, despite only being five inches tall.
Paige's favorite fairy tale suddenly becomes real, bringing her face with her past life as an evil enchantress, and a knight in shining armor. Meanwhile, Phoebe and Piper attempt to back in time to vanquish Paige's evil self, but end up trapped in the Dark Ages.
The Source messes with Piper's mind, sending her into a deep coma. Phoebe and Paige must find a way to wake her up fast, before The Source convinces to give up her powers while in her delusional state.
While considering Cole's marriage proposal, Phoebe is confronted by his demonic past, in the form of the widow of a man her murdered. Also, Paige encourages Piper and Leo to test out whether they are ready to have children.
Songs: Heather Nova -- Like Lovers Do
The sisters must stop a group of warlocks that are systematically enslaving the world's muses, and using their creative inspiration for evil purposes. Meanwhile, Cole is hurt by Phoebe turning down his marriage proposal, and also frustrated by his inability to protect her without his demonic powers.
Paige has unresolved guilt issues over her role in the death of her adoptive parents, so Leo takes her back in time to relive the events leading up to the accident that killed them. Elsewhere, Phoebe and Cole are possessed by the spirit of two 1950's outlaws, and Piper must stop them before the ghosts get married using their bodies.
While serving on a jury during a murder trial, Phoebe has a premonition that shows that the defendant is innocent, despite the overwhelming evidence to the contrary. As Phoebe stalls the deliberations, Piper, Paige, and Leo work to find the real killer.
Paige discovers that a 11-year-old runaway is a Firestarter, and takes him home so that the Charmed Ones can keep him safe. The sisters discover that his foster parents are demons, and plans to raise the child to be evil. Elsewhere, Cole proposes to Phoebe using her grandmother's ring, but the trinket carries an odd curse.
The Source breaks an ancient agreement between good and evil, and taps into an ultimate power source known as The Hollow. This all powerful vapor has the ability to consume the powers of any supernatural being, good or evil.
Songs: Natalie Inbruglia -- Goodbye
Phoebe gets cold feet about her upcoming marriage to Cole, and summons both a young and old version of herself to help her make a decision. If only she knew that The Source was slowly taking over Cole bodies, and that The Seer has convinced The Source's chief rival to kill the Charmed Ones.
Phoebe prepares to get married, while completely unaware that The Source now holds complete control over Cole. Meanwhile, The Seer informs The Source that if the marriage is performed in a certain ritualistic way, he and Phoebe's future son will grow up to be the most powerful evil being on Earth.
Living with two married couples leaves Paige feeling left out, and the situation escalates when she becomes convinced that Cole is still evil. For his part, Cole summons his contacts in the underworld to get her out of the way.
After 60 years of looking, two old ghosts from Leo's past finally catch up to him, and demand revenge for his perceived slights against them. Unfortunately, it's his wife Piper that may end up paying the ultimate price.
A Vampire Queen has aspirations to unseat Cole as the next Source, and orders her underlings to attack and turn Paige into a creature of the night. Before she can fully transform, she must feed on the living, and the Queen happily encourages her to feast upon Piper and Phoebe.
Songs: Dropline -- Graduation Day, Rusted Root -- Welcome To My Party
Phoebe tells Piper and Paige that she is pregnant with Cole's baby. The celebration is short-lived, as Piper and Paige team up with a wizard to stop the crowning of the new Source, unaware that it will be Cole and that Phoebe will be his queen.
As Phoebe comes to accept her new role as Cole's Queen, she still can't help but want to prevent the death of an innocent that she sees in a premonition, and asks her sisters for assistance. Also, The Seer plots to steal Phoebe's baby, and claim its limitless demonic power for herself.
As Phoebe's demonic unborn child continues to develop, The Seer sets her plan to steal the child into motion. She plans to raise the baby to be the new source, bypass Cole entirely, and prevent another demon from ever taking the throne of the underworld.
The sisters have a tough decision to make, as the Angel of Destiny offers them a chance to relinquish their powers and live normal lives as a reward for vanquishing The Source of All Evil. Their decision is delayed when an FBI Agent puts them under surveillance, and the real Cole begs for their help from the purgatory realm he is trapped inside.