S3·E17 The Joke's on Catwoman

Following a tip from Batgirl, the Dynamic Trio meet up at the Grimalkin Novelty Company, hideout of the Joker and Catwoman. There, they overhear the arch-criminals' plot and secretly trail them to a stash of hidden gunpowder. A careless mistake spoils the villains' evil plan, however, and they are captured and brought before the Gotham City judge. But when the jury seems less than interested in justice, courtroom mayhem ensues.