S1·E13 The Thirteenth Hat

Jervis Tetsch, aka the Mad Hatter, is abducting all the jurors who convicted him of a previous crime wave. He is also taking their hats. His final target is none other than Batman, who provided the key testimony in the Mad Hatter's trial. Batman and Robin have the Mad Hatter and his gang cornered but the criminal mastermind manages to encase the Caped Crusader in plaster of Paris.