Elsewhere in Arkham City, Catwoman perches on the edge of a tall building, her inquisitive eyes trained on a large metal door labeled, 'Confiscated Goods Vault'.

"Hmm...looks like the detective will be busy with the Joker for a while. Good." Catwoman says to herself. "Gives this kitty some time to play." She says, looking at the claws on her gloves. "So, what next? Help tall, brooding and handsome...or help myself to all the loot Professor Strange has locked up in that vault of his?" She ponders, unable to come to a decision. "I know. Difficult choice, right?" She then pulls out her phone and looks at it. "Hmmmm, what will it be? Find Croc and have him rip a hole in the vault? Ask Penguin for some explosives? Hmm, not my style." She then notices a flower shop with some familiar looking vines sprouting out. "I always prefer a woman's touch in these situations. Stay where you are, Ivy. I'm coming to get you." Catwoman says, not noticing Hulk wandering the streets as she jumps across rooftops to reach her apartment. "I need to get my kit from my apartment. No way can I face Ivy without my things. I'd be naked without them."

After dealing with some pervy goons who wanted to 'have some fun' with her, Catwoman reaches her apartment and enters through the window. "It's good to be home." She says as she exits, carrying some caltrops and bolas. "Okay, Selina. Time to find Ivy. Let's hope she's forgiven me. Pfft, of course she has. She wouldn't hold a grudge. Not on me..." As Catwoman leaves, she overhears Hulk fighting some thugs, winning once again as Catwoman smiles and jumps down to the street, looking up at him. "All these years, and you still put on quite the show." She says seductively, putting her hand on her hip.

"Says the hot woman in the skintight outfit." Hulk remarks with a grin as he crosses his arms.

"What can I say? It shows off my curves." She says with a cute giggle.

"Among other things." Hulk remarks, sneaking a peek at Catwoman's breasts.

"What can I say? Men love to look at my goods..." Catwoman says seductively, rubbing her gloved hands along her body as well as her big breasts and her shapely butt.

"Heh. No argument there. What are you doing here?" Hulk asks as he sits on a crumpled car.

"Well, I was on my way to see Ivy, get her to help me break into Strange's vault-"

"Wait. Ivy? Ivy's alive? I thought she died at the asylum." Hulk says in genuine surprise at Ivy still living as he stands up.

"Nope. She's alive and...somewhat well. I'm on my way to ask for her help. Would you...?"

"Like to come with?" Hulk finishes, to which Catwoman nods. "Why?"

"Well, we are friends, last time I checked. Plus, Ivy...might be holding a grudge."

"What'd you do..?" Hulk asks reluctantly, thinking Catwoman must've done something pretty bad.

"I...might've forgotten to water a plant of hers." She says almost as if she was ashamed of it.

"Oof. Bad kitty cat." Hulk remarks, to which Catwoman lightly giggles in embarrassment.

"Yeah...I could use some backup." She says. "Just in case."

Hulk sighs as he looks at her. "Why not? Got nothing else to do here."

Catwoman smiles. She always liked to hang out with Hulk, especially if she got plenty of opportunities to tease and seduce him. "Alright then. Let's go see the other green person...besides Croc."

"Croc is in Arkham City too?" Hulk asks, to which Catwoman nods. "Just...fantastic! Who's next, Calendar Man?"

-Ivy's Hideout-

Ivy and Hulk enter an abandoned building of some kind that is covered in overgrown vines and various types of flora.

"Ivy's a real plant lover..." Hulk softly says as he looks at the overgrowth of plants.

"That's a mild understatement." Catwoman remarks slyly. "Hello? Ivy? You here?" She asks, Poison Ivy's ethereal voice calling out in response.

"You shouldn't have come here! Mm...Hulk. Old friend. Long time, no see...again." Ivy says as she appears behind some bushes, smiling at Hulk, but sneering at Catwoman.

"Oh, come on. You're not seriously going to hold that against me forever, are you?" Catwoman asks exasperatedly.

"You killed them all!" Ivy yells at Catwoman accusingly.

"Oh, they were just flowers, Ivy. I'll buy you some new ones." Catwoman says before a vine bursts through the floor and wraps around her legs, pulling her to a lower level of the building.

"Ouch." Hulk replies to Catwoman as he looks at Ivy, slowly walking up to her. "Ivy...I thought you were dead."

"No need to apologize, my beautiful, strong green man. Like I said...you could never hurt me. It's her I'm mad at." Ivy says sweetly to him before looking at Catwoman with pure hatred.

"Come on, Red. Can't we just-?" Catwoman begins to say as a plant pod bursts open, releasing a bearded inmate, as well as several large inmates, their eyes glowing green. They were being controlled by Ivy. "Pammy, here's an idea. If you want a boyfriend, how about the dating route? Beats this voodoo crap."

As Catwoman fights the men, Ivy cackles as Hulk and her watch the fight. "I've spent weeks perfecting the toxins that will destroy your pathetic meat sack of a body."

"Personally, I think she's got a great body." Hulk says to himself as Catwoman climbs to the top floor after beating the henchmen.

"Look, Red, I just need your help." Catwoman says in desperation.

"Never..." Ivy says seductively as a long, thorn covered vine wraps around her, pinning her arms behind her back as it hoists her into the air, dangling the sexy cat burglar upside down as Ivy approaches her. "You've got some nerve, Selina. Coming here after what you've done."

-Sionis Steel Mill-

Manager's Office

Batman's vision starts to blur as he comes to. Half an hour has passed since Batman was knocked unconscious by Harley. As he awakens, Harley approaches him and reaches for his mask, only for Joker to call out.

"Get back here, Harley!" He says with authority.

"But I wanna know who he is, sweetie..." She whines.

"No one's who they say they are, my dear. Why spoil the fun?" Joker asks as he coughs.

"It was all a lie. There's nothing wrong with you." Batman says, thinking he has everything figured out.

"Nice of you to say, but you of all people should know..." Joker says as he comes into the light, his face covered in hideous scars and boils. "...There's plenty wrong with me." He finishes with a sickly grin. "Take my blood for example. Hehe. I wish somebody would. This stuff is killing me!" He says as he holds a small vial of his own blood, presenting it to Batman, who is tied to a wheelchair.

"Why should I care?" Batman asks.

"Hehehehe! Because now...there's a teeny little bit of me in you too, Bats." Joker says, prompting Batman to look at several blood bags filtering its contents into his body. "Oh, come on. Don't tell me it's not what you always wanted." Joker teases as he leans closer to Batman's face. "Look, we're running out of time. I need your help. I nearly had a cure; it was so close and then it was taken from me."

"So we both die. I'm fine with that." Batman says coldly.

"Are you?" Joker asks as he looks behind his back at Batman. "Imagine it, sucking down that last breath, knowing that Gotham is doing the same."

"What are you talking about?"

"Oh, didn't I say?" Joker teases as he sits on Batman's lap. "I've spent weeks shipping samples of my blood to emergency rooms all over the city." Joker explains as he walks away from Batman again.

"So that's Protocol Ten. Poison Gotham. I expected more. Even from you, Joker."

"Protocol Ten?" Joker asks, letting out a fake gasp of shock. "Never heard of it." He approaches Batman and puts his mouth to his ear. "Hold tight..." He whispers before kicking the wheelchair out the window. "I'll be in touch!" Joker yells out as Batman plummets to the ground below.

-Later-

Several minutes pass as Batman wakes up after hitting the ground. He groans as he slowly stands up, hearing a carnival ringtone coming from a cell phone taped to his chest. He tears it off and answers it.

"I'm listening." Batman says as Joker appears on the screen.

"Is someone feeling a little down?" Joker asks teasingly, though Batman isn't amused.

"What do you want?" Batman asks, wanting him to get to the point.

"Oh, Bats, cheer up. It won't kill you...Oops. Hehehehehe!"

"Where is the cure? Who has it?"

"I had our cold-hearted friend Mister Freeze making it. But he's gone dark on me."

"I'll find him."

"I bet you-" Joker says before being cut off as Batman crushes the phone by squeezing it with his hand and sliding the phone's SD card into his gauntlet.

"Alfred. Joker's poisoned me. He may have poisoned Gotham too. Mister Freeze has the only cure." Batman says into his cowl.

"What are you waiting for, then? He's in Arkham City. Find him!" Alfred says sternly, not wanting Batman to waste any time.

"If only it were that simple. He'll be somewhere cold. He needs to be kept at sub-zero temperatures to survive."

"Hmmm. I don't wish to worry you...but it is the middle of winter out there." Alfred says worriedly.

"I noticed. I've calibrated the cowl to track heat signatures. I'll find the coldest point in Arkham City." Batman says as he hangs up and presses a button on his belt. "That'll activate a device on Hulk's belt that'll give him my location. It also doubles as a panic button. He'll come running to me like a loyal dog." Batman says to himself as he glides across the skyline to track Arkham City's coldest locations.

-Ivy's Hideout-

As Ivy contemplates how to torture Catwoman, Hulk's belt begins to beep, signaling him to go to Batman's aid. "Damn...Sorry, ladies...but I'm needed elsewhere." Hulk says.

"Hey! Don't you dare leave me here! Ivy will kill me!" Catwoman shouts in protest.

"No. I'll simply torture you..." Ivy says cruelly, smiling at Catwoman's predicament.

"See? She won't kill you...I hope." Hulk says as he approaches the main door.

"Hulk." Ivy says, making Hulk look back at the green-skinned seductress. "It's great to see you again, my love." She says with a suggestive wink, making the green-skinned goliath blush slightly as he nods.

"You too, Ivy. Don't kill her, okay?" Hulk asks.

"As you wish...my dear." Ivy says seductively, making Hulk blush once more as he departs, leaving Catwoman at the 'mercy' of Ivy as several vines approach Catwoman, wiggling slightly.

"Hulk!" Catwoman screams loudly as Hulk exits the building and leaps towards the Steel Mill, but Batman is no longer there...

-GCPD Building-

Batman arrives at a seemingly abandoned GCPD building and enters, coming across several of Penguin's men, who are all armed as they pace around a forensic's lab. Several minutes pass as Batman takes down all but one of the men, who drops his gun in a sign of surrender as Batman clutches his throat.

"Where's Freeze?" Batman asks as he lifts the thug off the ground.

"He's in the museum. Penguin's got him!" The goon answers almost immediately, clearly fearing what Batman would do to him if he didn't say anything.

"I'll have to cut that tongue out of your head, boy. I don't like people tellin' tales on me." Penguin says angrily through an earpiece on the goon's left ear.

"No! I'm sorry, Mr. Cobblepot. He made me tell him." The goon protests fearfully to his boss as Batman knocks him out and tosses his unconscious body on the floor as Penguin's voice blares through the building's loudspeakers.

"You can have him, Batman. I'm safe and sound here in my museum. Try and get me if you want. I've got plenty of surprises ready for tou if you do, starting right now."

As Batman is just about to reach the front door of the building, a security gate slams in front of the door, trapping him inside as he immediately calls Alfred.

"Alfred." Batman says into his communication unit in his cowl.

"Hello, sir. Have you retrieved the cure from Mister Freeze?" Alfred asks, unaware of Batman's current predicament.

"No. There were complications. Penguin has got his hands on Freeze and he's trapped me in the GCPD building."

"You do realize that you will actually die if you don't get this cure soon?" Alfred reminds him.

"Thanks for reminding me, Alfred. I'll get out of here with plenty of time to spare."

"And how will you manage that, sir?" Alfred asks.

"The other Bruce..." Batman answers as he hangs up. A loud thud is heard outside the building, followed by the door being torn from its hinges by Hulk, who also lifts the security gate high enough for Batman to exit. "What took you so long?"

"Got held up. Sue me." Hulk remarks. "Where are we going now?"

"The Museum. Penguin has Mister Freeze locked up there." Batman says as he walks out of the GCPD building.

"What do we need that walking icebox for?" Hulk asks, unaware of Batman's current state of health.

"Joker poisoned me with his toxic blood. Freeze has the only cure. If I dont get it in time, I'll die."

"Ah. Let's go get him, then." Hulk says as the two heroes head for the Museum.

-Author's Note-

I think we all know what Ivy will do to Catwoman while Hulk and Batman are too busy dealing with Protocol Ten...