In Batman: The Long Halloween, Part One, Gotham City is plagued by a serial killer who strikes on holidays. Batman, along with his allies Commissioner Gordon and Catwoman, must unravel the mystery and stop the killer before more lives are lost.

Batman continues to pursue the Holiday Killer through Gotham City as he discovers more about the killer's identity and motives. Along the way, he encounters various villains and allies who may be connected to the case.