"The Night Before Zero"Edit
Batgirl captured the Joker with Batman and Robin close behind. While the questioned her, Joker fled and escaped in a helicopter. Another Robin looked on from a rooftop. Barbara told them that she'd not been shot, her father had. He'd died and Harvey Dent had replaced him as commissioner. Frustrated at not being able to convince them, Batgirl fled. Batman contacted Oracle - also Barbara Gordon. Joker broke into police headquarters and attacked Commissioner Dent. He bound him and placed Gordon's corpse in his chair. Batman was soon to respond. When he arrived, Commissioner Dent became Two-Face and Gordon awakened to chastised him for letting him and the Joker go. Batman had Robin check the grave, and it did not exist. Batman saw Batgirl leaving the Clock Tower; she'd visited Oracle. Batman then contacted Superman to ask what was going on about these people appearing in Gotham City.