The Joker's Blackgate Riot

Early in the morning of Christmas Day, a particularly destructive Code 10 riot broke out at the Blackgate Penitentiary, caused by the Joker.

Prelude
On Christmas Eve, a new criminal known as the Joker, at the time disguised as the criminal kingpin Black Mask, after torturing the warden, Joseph, and threatening his family, forced the warden to make security lax to engineer a prison riot inside the penitentiary. After Black Mask and several of his men, including the hired hitman Killer Croc, broke into the prison, a dispatch was issued requesting backup as Loeb and the news crew were taken hostage. Bruce Wayne, overhearing this dispatch, donned his identity of Batman and proceeded to go to Blackgate to quell the riot, but was too late to save Loeb.

After the Joker was exposed as being Black Mask and incarcerated at Blackgate Penitentiary, the Joker, while undergoing a psychiatric evaluation by Dr. Harleen Quinzel, managed to seduce and manipulate her to have an inside man inside the prison. She then slipped Joker some security codes, which he used to escape his cell and instigate a particularly destructive riot, releasing all prisoners except for Deathstroke, as the latter didn't want his time wasted especially when his attempt at collecting the bounty on Batman turned out to be such. This resulted in the staff sending a dispatch requesting assistance, which Batman managed to barely respond to due to depression for nearly letting Alfred die at the hands of Bane (who broke into the Batcave and caused a lot of destruction to the place and trapped Alfred underneath the under-construction Batmobile.

The Riot
Upon arrival, Batman found several prisoners holding a trio of guards hostage and debating whether to kill them immediately or otherwise exact revenge on them. Batman then proceeded to beat up the guards, and informed the guards to get the gates open for Captain Gordon and the GCPD. He then accessed the main sewer system, and broke a weak foundation in the floor. He then found the water in one part of the sewer system to be electrified alongside several dead bodies. After shutting off the electric box, Batman then scaled the sewer system, also bursting several pipes in order to continue forward. After escaping the sewer system, Batman found several prisoners who almost made it out and beat them into submission. Batman then continued onward just as Joker requested that everyone search for Batman and bring him in alive. Batman then arrived at a prison block where the guards and Harleen Quinzel were held hostage. After rescuing them, Quinzel pointed Batman towards Joker's location at the panopticon, and that the Joker's waiting for him. Batman then traversed through the prison searching out the panopticon, also dealing with several prisoners who attacked him in various cell blocks.

Upon locating the panopticon, Joker reveals he has Joseph hostage, and that he gave Bane a heart monitor that will charge a battery for the prison facility's electric chair, which will electrocute the Joker to death unless Batman breaks his one rule and kills Bane. Batman refuses, but Bane informs him that someone will die anyways, and he better fight with his resolve. Batman then reluctantly fights Bane. Joker also tells the two that he'll have the prison explode via a placed explosive that's set to go off if either of them remove the heart monitor, anticipating that likelihood. Batman is easily taken down by Bane, who does a backbreaker on Batman and crushes him underfoot. Gordon and the GCPD then arrives in the nick of time and shoots Joker's men to save the warden. He then tries to get Joker out of the electric chair when he discovered that the psychopathic clown had gotten himself into, but ended up being held hostage by the Joker instead and have his life put in jeporady. Batman then decides, after remembering one of Electrocutioner's taunts, that he temporarily stop Bane's heart long enough to fool the Joker into thinking he killed him. After using his electroshock gloves to place Bane into cardiopulminory arrest, Joker after getting free threatened to shoot Joseph when he stood up to the mass-murderer, only for Gordon to take the bullet (only surviving due to wearing his vest), with Joker then announcing that he's going to set off the explosives he set throughout Gotham earlier, also taking Gordon's gun with him. Batman then tells them to go after the Joker, explaining he needs to revive Bane before its too late, as he doesn't kill criminals. Bane, after his heart was restarted, then grabs Batman, and declares that he has no other option but to inject himself with TN-1 to stop Batman. Batman detonates the floor they were on.

Batman then has to stop Bane within ten minutes after learning more from Alfred about TN-1. After barely electrocuting Bane long enough to temporarily stun him, Batman tells Alfred that Bane's stopped, only to be thrown into a wall by Bane. During this time, all of the exits were sealed. He then restrains Bane to several electrodes, and hangs him upside down, with Bane unable to remember Batman's connection to Bruce Wayne due to the side effects of TN-1. He then goes to one of the prison blocs, where Joseph had been wounded by one of the Joker's snipers, with Gordon requesting a medical evac immediately. Killer Croc then tries to ambush Batman, but was instead grazed by a stray sniper round due to Gordon, in anger at the sniper for harming the warden, interfering with his shot. Batman and Gordon then proceeded to work together in fighting off several remaining prisoners. Gordon then stayed put while Batman pursued Joker to the Chapel (learning this from Joseph).

Batman then fights the Joker at the chapel, the latter irate with Batman after learning that the latter didn't actually kill Bane. He eventually attempts to slit Batman's throat with glass shards after the latter threw him at a stained glass window. After sustaining an extensive beatdown, Joker believing that Batman loves beating people up, requests that Batman brutally kill him. However, after briefly being strangled by Batman, the Dark Knight comes to his better senses and knocks him out just as Gordon walks in, with the police captain admitting that had he or his other policemen been in his situation, he would have killed the psychopath. After a brief exchange of words and returning Gordon's gun, Gordon tries to bring Batman under arrest, since although he did do good in stopping the riot, he still technically broke the law. However, he let Batman escape when Harvey Bullock contacted him.

Aftermath
Joker was returned to his cell, although not without the clown deciding that his future encounters with Batman will be "fun." Bane is also placed into incarceration for his role in the riots. Gordon then tells Barbara that she was the main reason why he let Batman escape, as well as that Batman might be the one to bring about hope for a less corrupt police force and law system. It was because of the events of this riot that Arkham Asylum was reopened, at the request of political activist Quincy Sharp. The riots also resulted in at least 21 prisoners escaping amidst the chaos, resulting in Batman, as part of a favor to Gordon, to round them up for the GCPD (as the police force was understaffed in large part due to the earlier riot).