While Batman prepares to become an official GCPD consultant, Catwoman relieves sword-crazy crime lord King Scimitar of his cash. The dynamic duo confront a mentally deteriorating Two-Face. And the Joker meets a new recruit.

Robin wonders if his partner is too close to the Two-Face situation, while at the new Bat-Signal's unveiling, Joker sends a message. And a Senator prepares to testify against the Penguin, unless the Penguin can get to him first.

Mayor Hill tries to enlist Batman's help as he prepares for the fallout from Catwoman's robbery. Bruce tries to get through to Harvey. Penguin acquires a rare, extinct centerpiece for his gala. And the Riddler escapes from Arkham.

Everything goes to hell when Penguin lures Two-Face to Scarecrow's fear gas plant. Robin infiltrates Two-Face's inner circle and replaces his lucky coin. Vicki Vale and Catwoman team up to take down the Mayor together.

As Gotham braces for the upcoming Valentine's Day attack, a drugged-up flash mob channels Joker-mania. Meanwhile, Riddler has writer's block. Penguin pushes Two-Face too far. And Batman confronts Catwoman about her plans for Mayor Hill.

The Riddler gets his groove back, and The Joker interrupts Bruce's night at the opera. Bruce and Dick go to the Museum's big unveiling, where Penguin intends to settle an old grudge.

With Mayor Hill closing in, Vicki Vale and Catwoman become roommates. Riddler plays with trains. Catwoman and Two-Face cut a deal. And with Batman distracted by a gas attack, Riddler traces his signal to the Batcave.

Batman scrambles to fend off Riddler's digital assault, and Penguin catches Catwoman red-handed at the Ice Age gala. Two-Face betrays Catwoman and partners up with Penguin. And someone poisons the drinks with Scarecrow gas.

Batman must outwit the Riddler before his hijacked ocean-liner crashes into Penguin's casino, while Catwoman gets to the dark heart of Project JoyCure. King Scimitar is on his way out of town - but Joker has other plans.

A frustrated Riddler pays the Joker a house call, and Joker's Valentine's Day plans commence. Reinvigorated, King Scimitar returns to get revenge on Catwoman and her tigers. And Batman and Joker collide, back where it all began.