While Piper is on holiday with Leo in another plane, Prue and Phoebe must face a series of deamons known as Guardians, who protect mortal murderers in exchange for the souls of innocents. After saving Daryl from a Guardian, Prue and Phoebe must testify in court, where they stumble upon an evil conspiracy. Phoebe falls in love with the District Attorney - Cole Turner.
The sisters must find a way to break a curse which turns a man into an Owl by day and his girlfriend into a Wolf by night. Meanwhile, Prue discovers a way to hold Piper and Leo's wedding without 'The Powers That Be' finding out.
With Piper growing more concerned that Leo will never return, Prue and Phoebe try to save a little girl and a fairy princess from evil Trolls. When Prue and Phoebe need Piper's help, her concern with Leo causes a spell to backfire, placing the girl in danger.
On Halloween, the sisters are pulled back in time to the 1600's to save a witch and her soon-to-be-born child from the hands of an evil witch who wants to raise the child evil. The sisters later discover that this situation may have more personal implications than they first imagined.
Prue becomes increasingly paranoid over attacks from the Triad, and the mysterious threat Belthazor poses. After the house is robbed, Prue is convinced the Triad is launching an attack, when the real culprit is more mortal than all three sisters realise.
After casting a spell to save an empath from feeling the emotions of the entire city, the man she frees reveals himself to be an near-invincible warlock. Meanwhile, Phoebe's relationship with Cole becomes turbulent when Cole tells Phoebe he doesn't want to see her anymore. With Prue's empathic powers growing, she urges Phoebe to go after Cole and save their relationship. Within a few hours, Prue's spell backfires as the warlock intended, causing her and her powers to lose control.
In an attempt to destroy the Charmed Ones, Cole enlists the help of Andras, a Warlock who magnifies anger into rage. When the sisters lose their magic after using their powers against each other, they are left defenceless against attacks from the Triad and Belthazor.
When the sisters discover that Cole is Belthazor, Phoebe must make one of the toughest decisions of her life: either vanquish her boyfriend or keep one of the most dangerous demons known to exist alive.
Piper is possessed by the spirit of an evil witch on the day of her High School reunion.
The sisters trace a mysterious Ice Cream Van who abducts children. However, the evil may not be who they initially suspect.
The sisters must stop a Warlock from executing his plan to steal specific powers from witches in his attempt to kill every White Lighter in the world.
Prue's old boyfriend is going around killing specific people using his powers, however he was always mortal. Prue is destined to deliver him from the evil which has promised him his dreams.
A shape-shifting warlock named Zile seeks the help of a high level priestess named Dantalian to wed him and Prue in unholy matrimony. The priestess has her own agenda, and ends up casting a spell making Prue and her sisters evil so that she can obtain the Book of Shadows--thus making her invincible.
When Phoebe feels the pain of an injured American-Indian ghost she sees in a deserted town, Prue travels back in time to the mid-1800s to save the man, and Phoebe, from death at the hands of a local thug.
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.
Prue must come to grips with the death of her mother when she is able to see the Angel of Death.
When a witch's familiar turns evil, the human product tries to get himself killed by the Halliwells nine times because then he will become a powerful and immortal warlock. Meanwhile, three and a half years in the past (before the sisters' powers were released) they must come to grips with the death of Grams and then the departure of Phoebe to New York.
A demon turns people into the embodiment of each of the deadly sins, including the Charmed Ones and Leo.
Cole poses as Belthazar to infiltrate an internet organization run by evil, that plans on controlling the world's information flow on the internet. Meanwhile, the sisters must vanquish the warlock posing as the company's manager without exposing Cole's role in the situation.
The evil Brotherhood plots to sabotage Cole's relationship with Phoebe in an attempt to turn him back to evil. Meanwhile, Piper's power develops with some explosive results.
When a banshee attacks and kills a neighborhood man, Phoebe has a premonition of another kill by the banshee while adding on to the Belthazoar section of the Book of Shadows (causing her to think Cole did it). When the sisters cast a spell to make Prue able to hear the call of the banshee without being damaged, it turns her into a white dog. However, when Prue gets hit by a car, Phoebe's remorse causes the banshee to attack her, turning her into a banshee.
When the Halliwell sisters are exposed as witches on Nation-wide TV, they form a pack with The Source to reverse time and undo the damage. However, in the process, one of the sisters makes the ultimate sacrifice, placing the Power of Three in mortal danger.
