There are big changes brewing in Gotham, but if Batman (Will Arnett) wants to save the city from the Joker's (Zach Galifianakis) hostile takeover, he may have to drop the lone vigilante thing, try to work with others and maybe, just maybe, learn to lighten up. Maybe his superhero sidekick Robin (Michael Cera) and loyal butler Alfred (Ralph Fiennes) can show him a thing or two.