-Patient Handover-
Batman stands in the middle of the room, cut off from Bruce, Commissioner Gordon, and the others as several inmates run out of their cells and surround Batman, ready for a fight.
"Ladies and maniacs, I apologize for this interruption to your regular entertainment." Joker says as his voice blares from a loudspeaker as he safely observes the fight. "Up until a few seconds ago, I was going to kill everyone in the room and then watch cartoons, but then...well...you know how I do love a captive audience."
Batman keeps fighting, throwing punches and countering the thugs' attacks. In less than a minute, all the thugs laid on the floor, unconscious.
"I'm just warming you up, Bats. Fresh from Blackgate Correctional Facility, with a combined sentence of 752 years. Ding, ding, ding, ding, ding! It's round 2!" Joker announces as more goons are released from their cells for him to fight. "Sorry, Bats. Gotta run. I've got places to go, people to slay."
Batman rushes to defeat the thugs so he can go after Joker. Soon, those thugs are down as well.
"The system's jammed. We're stuck in here. Joker's in full control of the security gates." Gordon says, unable to help in any way.
"I'll find a way out! Bruce, try to contact the Avengers, the Justice League. I'll try to get the Teen Titans on my end. Gordon, try and contact the Warden. Let him know what's happened. I'll be back." Batman says. Bruce nods as he uses an earpiece to try and contact his fellow Avengers, but no answer. He tries again to contact the League, but same results.
"Don't make promises you can't keep, Bats." Joker interrupts. "I'm in control of the Asylum. You and Brucey over there aren't going anywhere I don't want you to. Understand?"
"If you think I'll let you run-" Batman begins to threaten Joker, only to be interrupted again.
"Blah, blah, blah. Always with the hero speak. I'm getting bored of watching you. Why don't you just come find me...?" Joker asks as he deactivates the security gate that was separating him from Batman.
"You know it's a trap." Gordon says over the intercom.
"Of course it is." Batman says almost emotionlessly.
"Batman, I tried contacting the others. They're not responding." Bruce says through the loudspeaker.
"Joker must've blocked their communications somehow." Batman surmises the situation as he heads down the hall after Joker. After disappearing from their view, Batman presses his fingers to the earpiece of his cowl. "Oracle. Can you hear me?"
A female voice answers him. "Loud and clear. What's up?"
"Joker's escaped custody. He's running free in Arkham."
"Do you need anything? Is my dad still there?" Oracle asks.
"Commissioner Gordon is safe. Joker's not far ahead. I'll stay in contact." Batman says as he ends the communique with Oracle to resume his chase.
-Patient Pacification Chamber-
Batman enters a room where a couple of guards stand behind another security gate.
"What's going on?" Batman asks, getting the guards' attention.
"Batman! Thank God! It's Zsasz. He's got Mike. He's strapped in the chair. Zsasz has totally lost it!" One of the men says, clearly scared for his friend's well being.
"Wait here." Batman says, intent on stopping Zsasz.
"You can't! He'll kill Mike if he sees anyone trying to get close." The guard says in protest.
"He won't see me..." Batman replies as he walks past the guard. A bald man with scars all over his body stands in the center of the room, an Arkham guard strapped to an electric chair.
"I see anything that looks even a bit like a bat and this guard dies. Do you hear me?" Zsasz asks as he pushes a button, surging electricity through the restrained guard who shakes in response to the pain.
"Unnnnngh!" Mike gurgles painfully.
Batman grapples up to a gargoyle and flanks Zsasz Dom above before gliding downward and kicking him. Before Zsasz could recover, Batman leaps onto him and knocks him out cold with a punch to the back of his head. "Someone put this animal back in his cell." Batman coldly says as he releases Mike from the chair. Suddenly, a TV monitor hanging from the wall turns on, revealing a girl dressed like a jester. Harley Quinn.
"Can ya hear me? Is this thing on?" She asks. "Oh, hiya B-man. Harley Quinn here. How do you like my new uniform? Pretty hot, huh? Oh, I got something to show you." She begins to rush away only to stop. "One second, B-man." She leaves the screen, returning with Warden Sharp, who is strapped to a rolling chair, and has a piece of tap covering his mouth. "I'm now subbing for the old man. Old Sharpie's never been happier..." Harley says as she straddles her leg on his lap and leans his head close to her chest. "In case you haven't figured it out, today's the Joker's big homecoming, and you're the guest of honor."
"You have one chance to surrender, Quinn." Batman says gruffly.
"Tempting, Bats, but no dice. Now the inmates are running the asylum. Well, technically they're Joker's goons shipped in from Blackgate, but you get the idea. Bye bye for now!" Harley says in response before shattering the camera with the Warden's cane, cutting off her connection to the TV.
After this occurs, Batman is contacted by Oracle. "Batman. You picking this up?"
"Oracle, I'm here." He says in answer.
"Arkham Island just vanished off the network! I tried contact in the Teen Titans, but no response."
"Same with the Avengers and the Justice League. He's in control of the security system. He's probably isolated it from the grid."
"Well, that's not all he's done. All police feeds are reporting he's placed bombs all over Gotham. Says he'll detonate them if anyone sets foot on Arkham Island. It's being suppressed at the moment, but the story will break any time now." Oracle says.
"He's lying. It's just a diversion to keep people away." Batman says, knowing that Joker is trying to trick the GCPD into not interfering with whatever he has planned.
"Wait. How do you know?" Oracle asks in disbelief.
"I know him." Batman answers before cutting the transmission. "Harley thinks she has me trapped in this chamber. She never was very bright." Batman finds a way out: a ventilation shaft. He grips the side of the vent covering and tears it off the vent with his bare hands before entering the shaft.
"Batman, I'm patching you into the guard radio feed." Oracle chimes in.
"Steve, more Blackgate prisoners. By the boiler!" A guard yells out over said radio feed.
"Who's that behind them? Oh, my God...it's Joker. He's free. How'd he break out?!" Another guard says before the radio frequency suddenly cuts off.
"Sorry, feed's down. Comes are up and down like crazy. It's not good. I'll keep trying." Oracle says before ending the call as Batman kicks down a vent cover, exiting the shaft he was crawling through.
-Processing Corridor-
Batman enters a room with a large container hanging over a dark pit. Joker is standing on said container, giggling at the sight of Batman.
"What took you so long?" Joker asks, only for Batman to answer by pulling out a batarang and hurling it at Joker, but he ducks underneath it.
"There's no escape, Joker. I will find you." Batman says defiantly.
"Oh, I'm counting on it. Just not yet!" Joker stomps his foot on the container, making a door fall forward as a strange, muscular humanoid creature slowly exits. "Oooh. He's a big one."
The strange creature leaps down, landing in front of Batman and roaring at him. The creature picks up one of the unconscious Arkham guards laying on the floor and tosses him at Batman, who easily dodges his attack. The beast then charges at Batman, but dodges him again like before. After a few minutes of dodging the creature as it tries to punch Batman, the creature clutches its chest before gripping its head and groaning in excruciating pain before it collapses to the ground, dead.
"Well, that was unexpected, wasn't it? Oh well." Joker says in response to the fatality. "Note to self, need stronger test subjects." He says under his breath. "Seeing as how I'm feeling generous, I'll give you this one for free. Knock me off, I dare you. End this! Pull the plug! Stop me once and for all!" Joker proclaims.
In response to this, Batman pulls out another batarang, but holds back and puts the weapon away, receiving a laugh from his enemy.
"Hahahahahaha! You're getting too predictable, Bats! Well, I'd love to stay and chat, but I have a party to organize. I've got guests flying in from all over Arkham. You'll see..." Joker teases as the container is hoisted away by the track it's attached to, separating him from Batman.
"Ah...my head!" An Arkham guard says in complaint as he slowly regains consciousness. "Batman! Over here!" He deactivates the security gate separating him from Batman. "They came out of nowhere! I dragged Jerry in here, powered up the gate. Must've passed out."
Batman tilts his head towards the door Joker left through. "Joker went through that door. What's on the other side?"
"We call it Extreme Isolation. Only way in is via the transport system." The guard replies.
"Open it!" Batman says impatiently.
"Not a problem. I just need to call in another cell." The guard says as he prepares to have another container brought in. "Okay. Wait. Something's wrong here. The main security loop is locked."
The Joker suddenly appears on a monitor. "Having a little trouble up there?"
"Joker." Batman says in frustration.
"You were expecting maybe...Two-Face?" Joker quips.
"There's no escape, Joker." Batman says without any emotion.
"Silly Bat! I don't want to escape. I'm having way too much fun. I even have you here to keep a smile on my face."
"Not for long...!"
"Really? We'll see. Ta-ta. Oh. I forgot to say. Just in case you were planning on following me, I've arranged a little insurance. Gordon and Bruce are on their way to Harley as we speak." Joker says as he shows Batman security footage at Patient Handover. Boles knocks out Bruce and subdues Gordon before he can react.
"Officer Boles." Batman says in reaction.
"Hahahahahaha! If I see you try to follow me, they die. Harley is looking forward to it. Maybe I'll film it and post it on the Internet." Joker says as he cuts the video feed.
"The transport system is down. Best I can do is open the door you came in. Sorry." The guard says.
"I should head back to the holding cells. Boles wasn't too smart. He'll have left a trail." Batman says to himself as he leaves the room.
-Transfer Loop-
"Batman! What happened?" Oracle asks.
"Joker's escaped. He's sealed himself off. He's got your father! Bruce got captured as well."
"Dad...!"
"Don't worry. I'm getting them back." Batman says assuredly.
"OK. I know...but-" Oracle begins to say, only to be interrupted.
"Oracle, I'm getting them back. Joker will not win. I won't let him. I'm starting where they were taken. A guard named Frank Boles attacked them. If I find Frank, I'll find Bruce and your father."
"Batman, hurry! Please...!" Oracle says impatiently.
As Batman heads back to Patient Handover, Joker appears on a monitor again. "I bet you're wondering how I did it. Was it a clue the great detective missed? Hehehehehehe! As for Frank? Oh, me and Frank go way back. I hot him out of a spot of...bother a few years ago. So, when I need security codes or an old man or a bothersome scince nerd to be clubbed to the ground, I know just the man to ask."
-Patient Handover-
Batman arrives and begins to inspect the area using his evidence scanner. He eventually finds a clue in the form of Boles' flask. "Boles dropped his flask. Sloppy! Let's see what the forensic scanner picks up." Batman says as HUD in his cowl starts scanning the area for traces of alcohol. "I can follow traces of alcohol from Frank's bourbon in the atmosphere." Batman says before contacting Oracle. "Oracle, I've got a trail."
"That's great. You follow it. I'm grabbing every reference to Arkham I can find. Might be useful later."
-Secure Transit-
An impatient guard is complaining about a slow elevator as Batman enters the room. "Come on, what's taking so long? Stupid, unreliable..." The guard mutters as he notices Batman. "How did Joker get free?"
"Be quiet..." Batman says as he inspects more of Boles' trail.
"What's going on?" The guard adds.
Suddenly, Harley Quinn lands in front of the two. "Uh, uh, uh, uh, B-man! Mr. J doesn't want you following us just yet!" She taunts as she presses a button on a detonater, making the elevator fall while she is yanked upwards.
"Get down!" Batman yells as he throws the guard out of the way of the elevator before jumping away himself as the elevator crashes.
"How did you like that, B-man? No way you're following us now. You're trapped down there till me and Mr. J are ready for you. Ha ha ha!" Harley taunts.