Phoebe returns from New York to San Francisco to live with his sisters because of money problems. But Prue, the elder one, does not want to because she does not get along with Phoebe. Prue accuses her young sister of going out with the man Prue wan engaged to even if Phoebe always denied her version. Piper has to manage her sisters' moods and plays the intermadiate to avoid all the problems she can.
The night of her arrival, Phoebe enjoys herself with the spirit board of her mother. But the arrow -which surprised Phoebe- wrote the word 'attic'. So she decides to go to the attic even if the attic is supposed to be definitively closed. She succeeds in opening the door, opens a trunk and finds a big book. She opens it and quickly discovers that it is a book of sorcery. She reads the first spell of this book and, without knowing it, she gives back to her and her sisters their powers. The Power Of Three was born. Prue, Piper and Phoebe will now have to learn how to use their powers with all the problems that it engenders. They have to fight against the demons for the Good to reign on Earth. But they also have to hide their powers.

After a three years life of witches, Prue dies killed by a Demon called Shax. Piper and Phoebe are now alone : the Power Of Three is broken. Piper, despaired by her sister's death, tries all the spells she knows to make her sister come back. But none worked. Instead, the spells, brought Phoebe and Piper with their half-sister : Paige Matthews. Paige is the daughter of their mother -Patty- and of her Whitelighter : Sam. Piper and Phoebe acheived to convince Paige to join them in their fight against Evil. From now, Paige's life totally changed.
The new Power Of Three was born and can continue the fight.