The Penguin appears to have gone straight. (Evidently the citizens of Gotham City have short memories; he tried the same trick in season one.) Not only that, he has emerged as the leading contender for mayor of Gotham City, thanks to a little-known provision of the city charter that permits felons to run for elective office. Mayor Linseed, facing almost certain defeat, convinces Batman to run for mayor. This displeases the Penguin, who doesn’t want to leave anything to chance. He lures Batman and Robin into a trap and, by episode’s end, things don’t look good for the Dynamic Duo. (thetvdb.com)