S1·E11 The Stone of Threbe

Phobos has finally found an indisputable way to find his long-lost sister: The Star of Threbe. Back in our world, The Silver Dragon (Hay-Lin's family business) is threatened when Blunk stinks up the joint with his new ""home"": a garbage dumpster. While the girls try to give Blunk a much needed bath, Cedric places the Star in his window shop and Cornelia's platinum-haired friend walks in and takes it. Now when the girls try to change back, they find themselves stuck in Guardian form and powerless. Not knowing what to do, the girls race back to the Silver Dragon to enlist Mrs. Lin's and Caleb's assistance. In the meantime, Cedric sends a monster plant to Earth to tie up the Guardians while he makes contact with the Princess. The girls are forced to fight without their powers until the Princess returns the Star to Cedric, which leads the girls back to their powers. Unfortunately, Phobos and Cedric have who they're looking for, she just doesn't know it yet.