During a museum robbery, a partnership is formed between Catwoman and Penguin. But when Penguin double-crosses Catwoman before she can double-cross him, she and Batman have to stop Penguin before he unleashes his true plan: harnessing the power of Ra!

The GCPD find themselves dealing with a new threat in the form of Riddler, who has planted a bomb at Gotham's city hall. Fearing that Riddler will make good on his threat to destroy the city, Detective Yin, secretly aided by Batman, must work to solve a string of riddles that have been scattered throughout Gotham.

Firefly and Mr. Freeze make an unlikely pair as they join forces to plunge Gotham into a permanent winter. With the entire police force "iced over," The Batman is the city's only hope for survival.

Joker, dressed as Batman, begins a new reign of terror in Gotham. When the real Batman tries to stop him, Joker injects him with a poison that will cause him to laugh to death, unless he can come up with an antidote.

Killer Croc, a half-man, half-reptile, plans to submerge all of Gotham under water to carry out his scheme of plundering 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 that has found its way into the Bat-Cave and is wreaking havoc on the electrical equipment.

Despite intensive rehabilitation, Ethan Bennett once again takes the form of Clayface in order to seek revenge against Joker, the man who turned him into that monster. He's released on probation after standing trial for his crimes, 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. As a civilian, Selina Kyle befriends Bruce Wayne, but her intentions may not be so straightforward.

Spellbinder, a three-eyed mystic with the ability to induce both hypnosis and visions, sets his sights on stealing the valuable Eye of Sarkana – mesmerizing Alfred to be his personal thief.

Solomon Grundy, a legendary zombie, emerges from a swamp on Halloween to wreak havoc on Gotham. But Batman and Alfred discover that there is more to Grundy than there appears.

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. They finally decide to settle their differences by giving all of Gotham over to whoever is able to capture and discover the true identity of the Batman.