A mysterious villain known as the Riddler challenges Yin, secretly helped by Batman, to a number of riddles. Things are not what they seem from the riddles...

Firefly and Mr. Freeze team up to put their devastating plan into action: permanently putting Gotham City in a never-ending winter. Once the policeman's gala charity ball is put on ice, it's all up to the Batman.

Killer Croc, a half-man, half reptile plans to submerge all of Gotham in water in order to facilitate his plundering of the city.

Penguin discovers a sonic device that allows him to turn Man-Bat into his personal slave. Meanwhile, Alfred must deal with a raccoon which has found its way into the Bat-Cave and is wreaking havoc on the electric equipment.

Ethan Bennett is captured and put on trial for his crimes as Clayface. He's released on probation but he may find the temptations of a criminal life too great.

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!

Ragdoll, a triple-jointed contortionist, crosses paths with Batman and Catwoman while continuously trying to steal priceless artifacts. Also, Selina Kyle befriends Bruce Wayne ... but what are her intentions?

Spellbinder, a three-eyed mystic with the ability to induce both hypnosis and visions employs the servants of the rich to steal the Eye of Sarkana -- including Alfred!

Joker takes Detective Yin hostage, but once captured he refuses to tell of her whereabouts. Convinced it's the only way to learn Yin's location before she meets her demise, Batman uses a device created by Professor Hugo Strange to enter the bizarre brain of the Joker in search of an answer.

Joker, Penguin, and Riddler battle over control of the city, until finally deciding to settle their differences by giving all of Gotham over to whoever is able to capture and discover the true identity of the Batman.

After watching a movie about criminal masterminds, Penguin gets the idea to form a team of Gotham's greatest villains in order to finally take Batman down. Meanwhile, Batgirl and Robin must learn how to work together.

After the Joker's plan to make all the dogs laugh like hyenas is thwarted by Clayface (Ethan Bennett), he plans to prove himself to Batman by turning a new leaf. Meanwhile, actor Basil Karlo steals the mutagen responsible for Ethan Bennett for becoming Clayface and he becomes the new Clayface. Can Batman trust Ethan enough to help him stop Karlo?

When evidence from a series of art thefts by the Everywhere Man, a new costumed villain with the power to replicate, implicates Bruce's close friend John Marlowe, Batman believes there must be another explanation. Now, Batman must unmask the identity of the "Everywhere Man" and prove his friend's innocence.

After Batman apprehends Black Mask, his henchmen plan to spring him from Gotham P.D. so that Black Mask can activate his doomsday device. When Batman is captured, Batgirl and Robin must stop the villain on their own.

Hugo Strange infects the population of Gotham City with a virus that transforms them into zombies, and only Batman and Robin are left to find and distribute the antidote. But when Robin falls, only Batman can save the day. But not everything is at it seems ...

A thousand years into the future, the citizens of new Gotham must uncover the history of the Batman in order to stop a new Mr. Freeze.

The Bat Team goes up against an unstoppable thief who knows their every move.

The Riddler and Batman are dropped at the bottom of Gotham Harbor ... and the Riddler reveals his origins.

When Harleen Quinzell is cancelled from her television program, Joker takes an interest and decides to groom her as his new partner in crime, Harley Quinn.

The villains of Gotham City are disappearing, each one defeated and captured by an invisible vigilante named Rumor. Batman and Robin must defeat Rumor before he has a chance to execute the villains.

Bruce discovers that Wayne Industries is distributing alien technology across the world, and gains the aid of a mysterious new ally.

Martian Manhunter's prediction of an alien invasion by The Joining has come true. As Batman tries to stop them on his own, he learns that even working with a team will stop The Joining.

Batman and Superman find themselves teamed up when Lex Luthor begins his operations in Gotham City to take down his arch-nemesis, and employs a horde of the Batman's villains to do so.

Batman and Robin must battle Superman, who is under Lex Luthor's mind control, as the villain plans to launch a wave of robots and take over the world's armies.

Batman welcomes another member of the Justice League to Gotham as he teams up with Green Arrow when Vertigo, a villain who can affect people's sense of balance, arrives in the city with a diabolical plan.