The Spell to Resurrect a Love One is a spell that was written in the Book of Shadows by the Elders so that the Charmed Ones could bring back one of their loved ones. They had the choice to bring back either their long lost sister, their mother or their grandmother. After a very long debate they chose to resurrect their long lost sister Prue to help them fight off the demons in Demonland. 
- Hear now the Power of Three,
- Set all our troubles free,
- Bring back our sisters remains,
- Bring [Prue] back to our domain.
- The spell isn't specific to the resurrection of Prue Halliwell; the caster just has to switch out the name Prue for another loved one (e.g. Penny or Patty).