Prue begins experiencing the powers of an empath, thanks to a warlock, but she soons loses control. Meanwhile, Phoebe's relationship with Cole becomes turbulent when he tells her he doesn't want to see her anymore.

On the day of Piper's marriage to Leo, Prue's Astrally Projected-self adopts an uninhibited, wild personality that threatens to ruin the wedding and place Prue in jail for Murder.

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.

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.

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.

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.

The Seer plans to steal Phoebe's unborn baby so she can raise the child to become the next Source and prevent the throne from passing on to another demon. Meanwhile, the baby begins to take over control of Phoebe's body, which proves dangerous to Paige.

Piper, Phoebe and Paige come to the aid of Mylie, a Mermaid-turned-human, when she shows up looking for their help after a pact she made with an evil Sea Hag begins to go drastically wrong. Meanwhile, Phoebe attempts to divorce Cole, until he shows up claiming to want her back, Paige, attempts to juggle her new position as a full fledged Social Worker, as well as being a Charmed One, and Piper must protect her unborn baby, and face her fear of water.

When Phoebe must constantly save the life of her new boyfriend, a warlock shows up from the future, claiming that future Cole sent him in order to kill the boyfriend before Phoebe's dies instead. However, present Cole cannot allow this and tries to help the sisters protect Miles, but when the warlock decides to work on his own agenda, by stealing the Book of Shadows, it results in the death of two of the Halliwell sisters. The survivor must decide whether going back to change the past is the right thing to do.

Phoebe and Paige go to a summit meeting with the leaders of evil and discover that all magic - both good and bad - has disappeared enabling the leaders to steal Piper's about-to-be-born baby and welcome the twice-blessed child into the kingdom of evil.

In order to get close to baby Wyatt, the Crone steals one of the senses from each of The Charmed Ones, in an attempt to fool the child.

Now all powerful Greek goddesses, the Charmed Ones must try to not be seduced by their new powers and stay focused on vanquishing the Titans before they destroy all the whitelighters. Meanwhile, Leo must decide whether to become an elder or stay with Piper & Wyatt.

When three evil sisters magically steal the Charmed Ones' identities and powers, Piper, Phoebe and Paige must convince Chris that they are the real Charmed Ones in order to get their lives back. Meanwhile, Piper realizes that Wyatt needs time with Leo, who continues on his quest to find out who put him on the Island of Valhalla.

Paige finds herself transported back in time to an era of free love and free magic, where she discovers Grams, a peace-loving hippie, who is on a crusade to rid the world of evil through the magical power of love.