Charmed - Season 4 Episode 3 -

Piper is full of anger for the death of Prue and vanquishing as many demons as possible, jeopardizing her, Phoebe and Cole's lives. Paige "borrows" the Book of Shadow without permission of her sisters to cast spells to help her colleagues in South Bay Social Services office. When Piper, Phoebe and Cole fight against The Furies, Piper inhales a smoke released by one of the demons. Her anger is magnified and Piper is transformed in one The Fury.