Gordon offered to give her a police escort for her safety, but Babara told him that the police were the ones stalking them.Hearing her father mumble "so it's come to this", Barbara was surprised when he gave her a radio and list of channels that the corrupt cops use.While talking with Barbara, the GCPD SWAT Team tossed a smoke grenade into the room.
Barbara acted quickly, stole the makeshift Batman Suit and gadgets that the GCPD threw together, came in through a window up high, and announced herself as Batgirl.
She then proceeded to jump into the fray, took down all of Killer Moth's Henchmen, and disarmed Killer Moth of his trademark cocoon gun.
Shortly after Batman arrived with the Joker at Arkham Asylum, the Joker was escorted by a team of armed and armored security guards to the Holding Cells at the Intensive Treatment Center, when he broke free.
The Clown Prince of Crime killed a guard and a doctor in the area before he freed all of the prisoners that were housed in the Holding Cells.
As he arrived at the Patient Pacification Chamber, Batman contacted Oracle via his communications system. That proved to be wrong, however, as Frank Boles was secretly in the Joker's employ and he clubbed Gordon with a nightstick, kidnapped him, and regrouped with the Joker's partner-in-crime, Harley Quinn.