MIDSEASON RETURN: The title of this return story is “Pieces of a Broken Mirror.” The story picks up where it left off, with Penguin arrested by Jim Gordon and sent to prison. Tonight’ he’ll meet up with the future Joker there – while another famous Batman villain, Poison Ivy, finally comes into her own and declares her new identity. And she has one, too, because this episode marks the third actress on Gotham to play the role of Ivy Pepper. First came Clare Foley, wh