This is the spell that Phoebe found in the book of schadows in the loft. She sad the spell at loud and before she knowed she had activited the power of three!
Invoking The Powers Spell Hear now the words of the witches, The secrets we hide in the night. The oldest of gods are invoked here, The great work of magic is sought. In this night and in this hour, I call upon the ancient powers. Bring your power to we sisters three, We want the power, give us the power.
the 4 charmed sisters.
(season 4-8) Phoebe,Piper,Paige
Prue (Prudence) Halliwel 
Piper Halliwel 
Phoebe Halliwel
Paige Matthews
