Blinded by the Whitelighter

The Charmed Ones go up a powerful opponent when an ancient warlock, capable of sucking out and immediately acquiring the magical powers from his victims, begins systematically annihilating the whitelighters of the world. It is evident he has put together a long term plan and murders a powerful witch which triggers a cry, causing the Elders to ban orbing and withdraw whitelighters from Earth back to "The Heavens" while the Charmed Ones can deal with him. But the help from an old friend and co-worker of Leo, an interfering, infuriating, "by the book" Whitelighter breeds animosity between Piper and Leo, who were already experiencing friction over Leo's work. To resolve the issues, Leo turns over his charge to Natalie, but when she falls to a trap, he returns and realizes that the only way they can beat Eames, is to break all the rules. In the end, the Elders allow Piper and Leo to be officially engaged.