Depressed over the loss of the future version of Chris, Piper and Leo are forced by Phoebe and Paige to attend a Hindu wedding ceremony, where they are accidentally imbued with the powers of two Hindu gods. Phoebe and Paige must prevent them from using Piper and Leo's bodies to consummate their love, or the world will end. Elsewhere, Phoebe meets a new man, and Paige resolves to take over operation of the magic school.

Paige's attempts to save the Magic School are jeopardized when a student conjures Lady Godiva and the evil Lord Dyson. Dyson feeds off of humans' repressed emotions, and must be stopped from hugging Godiva before she can return to her time and complete her famous ride. Meanwhile, Phoebe doubts the abilities of the new male advice columnist at the paper.

Against Piper's wishes, Paige and Phoebe summon Grams for Chris' 'wiccaning'. In an attempt to end the budding sibling rivalry between Wyatt and Chris, Grams casts a spell on them, which backfires and turns the sisters back into bickering teenagers. This all leads to the Charmed Ones father Victor coming back to town to try to fix things. Also, Wyatt is attacked by a demon, and Leo is determined to find out who it was.

Paige encounters an infamous 18th century pirate Captain, who is cursed to grow old but never die. After he transfers the curse to Paige, Phoebe and Piper must seek out the Fountain Of Youth to reverse things. Also, Leo finds himself being manipulated by the disembodied voice of an evil creature, and the FBI once again investigates the Charmed Ones.

A demon is attempting to destroy his human half by hugging his remaining blood relatives. Paige casts a spell to prevent this, but accidentally stops all passings from occurring. Annoyed at Paige's messing with his plan, the Angel Of Death insists that Piper helps get things back to their proper balance. Also, Piper finds out upsetting news about Phoebe's future, and FBI Agent Brody reveals his reason for pursing the Charmed Ones.

The Elders have grown suspicious of Leo, and assign a new Whitelighter to the sisters. When the new Whitelighter is nearly cuddled by a pack of beasts, Leo is held responsible. Meanwhile, the sisters are surprised at the identity of the aforementioned beasts, Agent Brody informs Paige of a new possible threat to the family, and Phoebe parts ways with her boyfriend Leslie.

Agent Brody enlists Paige's help to solve a string of crimes, only to discover that the demon Sarpedon is capturing Guardian Angels in order to protect himself from a new powerful group known as Avatars. Meanwhile, Piper and Phoebe convince Leo to embark on a vision quest to deal with his issues, but finds himself having to make an impossible choice when he returns home.

While investigating a passing at the Magic School, Paige and Agent Brody are trapped inside an unfinished novel that was written twenty years prior. The pair find themselves in a 1930's film noir setting, and are chased by ruthless gangsters. Back in reality, the other sisters try to help Paige and Brody by writing clues into the story, and Leo tries to win Piper back after his decision to become an Avatar.

Leo reveals his new Avatar status to Piper, despite warnings from his overseers Alpha and Beta that she wasn't ready for that information yet. Piper is mixing a potion at the time, which messes up and rewinds time. Leo is given several chances to make the right choice in the situation, but each instance ends with a different disaster. Also, Darryl becomes suspicious about Kyle's past.

The Avatars insist that Leo protect former enemy The Seer, because she has information that could help them defeat the demon army. Leo finally admits that he is an Avatar, for good this time. Meanwhile, The Seer sends Phoebe a vision of a future without demons, the powerful demon Zankou is sent to take the Seer out of the picture, Brody shares a secret with Paige, and Phoebe and Darryl continue to look into Brody's shadowy history.

Still not completely convinced of the Avatars good intentions, Piper switches powers with Phoebe in order to experience her premonition of a utopian demon-free world. Sensing their vulnerability during this period, the demon Zankou attacks. Brody's desire tohug all Avatars out of revenge for his parents' passing, prompts Paige to take him back to the night they died. Also, the Elders learn that Leo has joined the Avatars, and aren't happy.

The Avatars are preparing to transform the world into a demon-free Utopia, but inform the sisters that humanity must be temporarily put to sleep to allow the time needed to wipe out any remaining demons. Kyle Brody still finds himself skeptical of the Avatars' true intentions, and tries to go to the Elders for help. Instead, he is kidnapped by the demon Zankou, and convinced to help stop the Avatars' agenda.

The Charmed Ones are enjoying their new peaceful utopian world, but Leo learns a horrible truth about the lengths the Avatars have to go to maintain an everlasting end to war. Leo then joins with the demon Zankou to overthrow the new rulers. Also, Kyle Brody is rewarded for his heroic efforts by the Elders, and is resurrected as a Whitelighter.

When Paige attempts to a hire a new teacher for the Magic School, she finds out that one applicant named Drake is an ex-demon who made a deal with an evil sorcerer in order to become human. Drake decides to convince the sisters that he has reformed, but the sorcerer won't abide that, and casts a spell that causes Drake to believe he is Robin Hood and that the owner of the local phone company is the villainous Prince John.

A friend of Darryl's is possessed by the spirit of one of the victims of a deadly 1899 cabaret fire thathuged hundreds, and Darryl goes to the sisters for help. It seems that the spirit is working on behalf of all the souls that remain trapped at the site of the blaze, due to the club's owner making a pact with a demon.

A stressed out Piper awaits word from the Elders about Leo's future, but is attacked by demons and ends up comatose. She finds herself in limbo between life and passing, and is surprised Cole's spirit waiting for her there. Elsewhere, the Elders try to manipulate Leo into giving up his family, and Drake has to face his impending demise.

Zankou sends his minions to attack Leo, in the hopes of luring the sisters into a battle, so that he can steal the Nexus from under their house. Also, young Wyatt is scared for his parents welfare, and proceeds to shrink them to doll size for what he believes is their own protection.

The Charmed Ones must stop a demon named Katya from opening the mythical Pandora's Box, and releasing all the horrors contained within. Meanwhile, Paige begins hearing the call to become a Whitelighter, and an Elder named Sandra suggests that Leo send her to save the life of an endangered future Whitelighter named Hope.

A beauty obsessed demon named Imara casts a spell on Phoebe, causing her to take possession of Phoebe's body and Phoebe to take her place in the underworld. Meanwhile, Paige's first charge seems to be drifting to the dark side, and Imara plots to take down Zankou through the Charmed Ones.

Wyatt's new imaginary friend is actually a demon named Vicus, who is attempting to gain the child's trust and turn him evil. Meanwhile, Piper tries to cast a spell to make her understand baby Wyatt, but it accidentally conjures up an adult Wyatt from the future. After Vicus curses Wyatt to become evil, the now-malevolent adult version kidnaps his child self to prevent the Charmed Ones from reversing the process.

Zankou embarks on a plan to make the sisters vulnerable, allowing him to sneak in and take the Book Of Shadows. When Phoebe sees a classmatehuged in front of her, and Paige loses one of her charges, Zankou decides to punish them by conjuring the spirits of all the dead innocents they failed to save. Also, Darryl has to chose whether to obey his superiors or continue to help the Charmed Ones.

After claiming the Book Of Shadows, Zankou prepares to open the Nexus, and claim its power. In a last ditch effort to stop him, the sisters goad him into coming after them instead. Undaunted, Zankou steals Phoebe's powers, and is able to anticipate the Halliwells' every move. Also, the law enforcement investigation into the sisters ratchets up a notch.