Batman deals with an arsonist known as Firefly and problems involving Gotham's mayor.

The Joker decides to take on the role of "Batman" and doses Bruce with Joker venom to create an arch-rival of his own.

Joker pirates the airwaves of Gotham in order to broadcast his crimes on TV as entertainment. When Detective Yin's overzealous new partner tries to bring the clown prince of crime down, he merely becomes Joker's latest "co-star." Batman must find where Joker is broadcasting from before he can carry out his plan to make Gotham die of laughter!

High-ranking Gotham officials begin to embrace environmental causes after the delivery of mysterious plants, and it becomes clear they're under the influence of ... Poison Ivy.

Inspired by the Batman/Batgirl partnership, the Joker decides to recruit his own sidekick and gain a partner in crime.

Maximillian Zeus, a millionaire who is also a Greek history fanatic, takes control of Gotham from the sky after losing to Mayor Grange in a re-election.