S06E04: The Power of Three Blondes

When three evil sisters magically steal the Charmed Ones' identities and powers, Piper, Phoebe and Paige must convince Chris that they are the real Charmed Ones in order to get their lives back. Meanwhile, Piper realizes that Wyatt needs time with Leo, who continues on his quest to find out who put him on the Island of Valhalla.