Hulk and Batman use their skills to make their way across Arkham City, eventually reaching the Museum, Penguin's home base. They get spotted by some of Penguin's goons, but easily beat them down with their superior skill and strength.

"It's stupid how many times they attack us." Hulk remarks as he crosses his arms.

"Agreed. You think they'd learn by now." Batman says in response before the two head inside the museum.

-Museum-

Once inside, the two heroes hear an announcer on the loudspeaker. "Welcome to the Cyrus Pinkney Natural History Institute. All visitors must be searched as part of our ongoing commitment to keep you safe and protect the unique collection we have on display." The announcement says.

"Clearly, it's been a while since this place had visitors..." Hulk says softly as he looks at the decrepit state of the museum.

Batman says nothing as they walk forward, only for some metal bars to pop up, stopping them from going any further as Penguin comes onto the loudspeaker. "I don't think I want you breaking into my home, Batman. Same goes for you, Hulk."

"Too bad, bird boy." Hulk retorts as he approaches the metal bars and easily tears them down, rendering the blockade pointless and nothing more than a slight inconvenience for the two heroes. As Batman activates his cowl communicator to contact Alfred, it comes up all staticky and incoherent.

"Something's blocking communication back at the Batcave. Penguin must be using military grade communication disrupters. The only way to solve this problem is to destroy them." Batman says.

"Yeah, but where are the disrupters? Something tells me they're not all in one place." Hulk says to him.

"Don't know...but I think I know how to find them." Batman says as he tunes his tracking equipment to locate the disrupters. "Let's go." He says as the heroes head outside.

-Outside-

Batman and Hulk traverse across the rooftops of Arkham City, coming across the first disrupter, which is on a large rooftop with some Penguin henchmen, who were clearly tasked with protecting it. Hulk grins as he lands on the roof, doing a dramatic roll as he easily contends with the thugs as Batman glides down to the roof.

"Too slow, Bat." Hulk says competitively.

"It's not a race, Hulk." Batman says as he looks at the large disrupter. "Hmm. The disrupter has three terminals attached. We'll need to destroy all three to shut it down."

"Or we could just do this." Hulk says as he lifts the cumbersome machine over his head and drops it onto the streets below, completely destroying it.

"Nice work. That's one jammer down. We should look for more." Batman says as the two resume their search for more jammers. It doesn't take them long to find the next jammer, which in being guarded by four men with guns.

"Too easy..." Hulk whispers as he leaps on the roof and lets the men shoot him, their bullets harmlessly bouncing off of him. "Idiots." Hulk retorts as he takes the men out as if they were flies. He then approaches the jammer and punches it multiple times until it was nothing but a pile of scrap metal. After that, Batman overhears a call between Penguin and his men.

"I just lost the signal to the jammers up top. What's going on?!" Penguin says angrily.

"We've only just managed to get below ground." A henchmen says in response.

"Just set the jammer up wherever you are. Do it now! Batman and Hulk are probably on their way down there! Understand?" Penguin asks impatiently.

"Yes, sir, Mr. Cobblepot." The goon says as the call ends.

"The signal's blocked again. Sounds like Penguin's final jammer was activated somewhere underneath Arkham City."

Hulk growls. "Great. We gotta go underground..." He mumbles to himself as the two heroes head underground via an old subway entrance.

-Subway Tunnels-

After several minutes of traversing through the maze-like tunnels, Batman and Hulk find the final jamming device, but it's currently being guarded by several of Penguin's men, all of which are armed with assault rifles. Batman flips on his detective vision, but it's all distorted.

"The interference is stronger in here; one of the thugs must be using a portable jamming device." Batman says, to which Hulk nods with a grunt.

"Leave it to me, Bat." Hulk softly says as he dispatches the goons, punching and body slamming them around until the room goes silent. "Clear!" Hulk calls out.

"Good. Destroy the jammer!" Batman orders to his green-skinned companion.

Hulk grunts in response to this as he easily lifts one of the subway train cars over his head and slams it into the jammer, completely decimating it. "Too easy..." Hulk scoffs.

"That was the last jammer. We should be able to get into the museum, now that my communication equipment is back online and fully operational." Batman says.

Hulk nods. "Finally. It's time I get to smash some more idiots..."

-Museum-

Hulk and Batman enter the museum, now able to waltz right in without a problem. However, it doesn't take long for a new problem to pop up, as the heroic duo see a man being harassed by some of Penguin's men, one of which is wearing body armor, though Hulk scoffs at this, as the heroes easily contend with the minor threat before attending to the man that was being harassed.

"You're safe now." Batman says assuredly.

"Thank God!" The man exclaims with gratitude.

"You may want to hold off on thanking Him for a bit. Who are you?"

"Sorry. I'm a cop. Gordon sent us in here." The man says. "I'm from the 13th Precinct, part of a strike team. Been in here since the beginning."

"Gordon is putting his own men in this dump?" Hulk asks himself, grunting slightly.

"If Gordon sent you, I assume you know the code?" Batman asks.

"Yeah. He said...Oh, man, what was it?" He asks as he struggles to remember what the code was before it finally came back to him. "It's 'Sarah'! The code is 'Sarah'."

"Simple code.." Hulk says in response.

"You're safe, officer." Batman assures the man again.

"It's Jones, Batman. Elvis Jones." The man says. "Gordon sent ten of us in here. Hopefully they're okay as well."

"Pretty stupid of the old man to send you in to begin with..." Hulk says, pointing out the absurdity of Gordon sending people into Arkham City.

-Gladiator Pit-

After leaving Elvis Jones behind, Hulk and Batman enter a section of the museum that resembles a gladiator arena, with large groups of thugs cheering as the two enter the room. Above the arena, a man limps towards them, his arm reaching out to them.

"Help...me!" He weakly says before groaning and falling down dead. Behind him was none other than Penguin, who was wielding an umbrella with a gun inside it, hi broken hand wrapped in bandages as he cackles at his kill. Hulk growls at the small man while Batman readies a batarang.

"Eh-eh. I wouldn't do that if I was you." Penguin says in warning.

"You ain't him, bird boy." Hulk retorts.

"True, monster. So true. Boys...show them what we got." After Penguin says this a large one-armed man-very similar to Mr. Hammer, walks into view, clutching another one of the officers by the neck. "So...you two here for the cops...the iceman...or me?"

"We only came here for Freeze and the hostages. But now...we're taking you down too." Batman says threateningly.

"Oh! Aren't you two scary?" Penguin sarcastically remarks, not taking either of the two heroes seriously.

"You're about to find out, shorty. Now shut up; you're giving me a headache!" Hulk roars out, annoyed by Penguin's constant talking and cackling.

"Am I?" Penguin asks as one of his men lights a cigar for him. "Listen. I'm what you might call a collector. If someone wants it, I'd like to think I got it. If I don't have it, I'll get it. So, here's the thing. Back there, I've got a cabinet with both your names on it, just waiting to be filled. As luck would have it, here you both are, standing exactly where I want you. Hahahaha! So...you going to be good boys and give up nicely?"

"You're not giving orders here anymore, Cobblepot." Batman says sternly as he glares at Penguin.

Penguin smiles. "I was hoping you'd say that. Look around you." Penguin says, prompting Hulk and Batman to see the large groups of thugs, separated from the main arena by security gates. "This horrible bunch of psychopaths are all begging to join up with me. Unfortunately for them, I only take the best, and today, best means whoever can kill you two. Come on out, lads. It's initiation time!"

The security gates open as the horde of goons rush in, prompting Hulk and Batman to get into fighting positions. Hulk grins as he effortlessly plows through the thugs while Batman swiftly deals with his own band of goons, punching and kicking them while Hulk simply punches them and tosses them across the room. Once they've all been dealt with, Penguin yells in frustration as he drops a cage into the arena, narrowly missing Batman. Much to the heroes' shock, a Titan monster climbs out and tosses its cage at the two, but Hulk punches it away with ease as the monster roars at them, only for Hulk to roar back. Hulk charges at the monster and locks fists with it. Like his previous encounters with Titan beasts back at the asylum, Hulk eventually gains the upper hand, punching his hideous opponent in the face and gut over and over. As the creature gets on one knee, breathing hard, Hulk lifts the monster over his head and tosses it into one of the electrified walls, knocking the creature out.

"Hulk strongest one there is!" Hulk roars out in victory, beating his chest like a gorilla.

Batman quietly scoffs at Hulk's boasting as he contacts Alfred. "Alfred, we found Penguin."

And Mr. Freeze? Have you located the cure yet?" Alfred asks through the communication device.

"No. Not yet. The situation is worse than I initially thought. Penguin has a supply of the Titan formula." Batman answers, only for Oracle to rudely butt in on the conversation.

"He's got what? How'd he get Titan off Arkham Island? What's going on here? Your suit's bio readings are spiking."

"Gee, that's rather rude, eavesdropping on a conversation..." Hulk says in response to Oracle joining the chat.

"Nice of you to join us, Oracle. Alfred, bring Barbara up to speed."

"Of course, sir." Alfred says politely as he ends the call.

Hulk grunts slightly. "Now what do we do?"

Batman looks at Hulk. "We go after Penguin."

-Later-

Batman and Hulk come across a wall of ice that's blocking their path. Batman pulls out his Explosive Gel gadget, only for Hulk to clear his throat, pointing out that he can get through the ice much faster. Batman puts the gadget away as Hulk rears his right arm back and smashes through the ice with one hit. However, as soon as the two walk on, they are shot by Penguin, who is using Mr. Freeze's ice gun.

"Stay right where I can see you two. You wouldn't believe the fight the old snowman put up. Still, I got what I wanted, and that's all that matters." Penguin mockingly says as another one of Gordon's cops runs across the frozen water, the ice cracking with each step that he took. He dodged several shots from Penguin before he fires a charged shot, which hits him in the ankle freezing him in place. "When you're both done in here, feel free to join me in the Iceberg Lounge so I can kick your asses again." Penguin 'coldly' says as he walks away.

After Penguin disappears from view, Hulk and Batman free themselves from the ice that restrained them as they growl in frustration at Penguin's actions.

"I hate that short bastard." Hulk says angrily. "He's such a jerk!"

"Me too." Batman replies with equal anger. He glides down onto the ice, only for it to crack violently upon landing. "The ice is too thin. I'll have to move slowly. Hulk, stay put. With your weight, you'll shatter the ice instantly."

Hulk growls softly, but nods his head. "Fine...but hurry. I hate waiting."

Batman approaches the frozen officer and frees him from the ice, grappling back up to the platform where Hulk stood, his arms crossed in boredom. "Are you from the 13th Precinct?"

"Yeah...There are two more guys in this room. Penguin froze them up, then...Well, I guess you guys saw what happened." The cop stutters as a result from being frozen.

"Uh-huh. We saw." Hulk says, his arms still crossed.

"I'll get them. You wait here and try to warm up." Batman says as he returns his focus on getting across the frozen water. As Batman slowly treads across the ice, a humongous shark bursts out of the water and bites at Batman, but narrowly misses him and retreats back into the water.

"Sorry, Batman. Did I forget to mention my little friend down there?" Penguin's voice asks as it plays through a loudspeaker. "Meet Tiny. Who would've thought a big fish could be so useful? Not me, that's for sure. He's like a mobile garbage truck. Whatever I drop in that tank, it just...vanishes. Poof, problem gone."

"Yeah. You forgot to mention that!" Hulk retorts to Penguin.

"If that's the case, how about we throw you in, midget?" Hulk mutters under his breath.

-Elsewhere-

Batman enters a prehistoric wing of the museum, in which three officers are being held hostage by Penguin's men. As per usual, even without Hulk backing him up, Batman is easily able to take the goons down as he approaches one of the officers.

"I saw you clear the room. Awesome work, man. The name's Tom. Tom Miller." The man says.

"You're part of Gordon's strike team. I've seen your file." Batman says.

"You have? I mean, yes, sir. Cobblepot's turned this place into a fortress. Someone ratted us out."

"You're safe now. There are just two more of you unaccounted for." Batman says assuredly.

"You try the Iceberg Lounge? Cobblepot likes to take us there to beat us. If we're lucky, that's where they are."

-Trophy Room-

After being unable to reach Penguin due to his ice gun, Batman wanders around some more, eventually coming across a room full of trophy cases, one of which was tropical island themed...and was holding Mr. Freeze, who was no doubt suffering greatly because of it. As Batman approaches a weak wall, the one-armed man from before clutches his throat and tosses him back, pulling a massive scythe from a sheath on his back as several smaller goons run in. Batman simply cracks his neck as he quickly contends with the goons, his mind mostly focused on getting Mr. Freeze out of his makeshift prison cell. Once they've been taken down, Batman uses his Cryptographic Sequencer to hack the door to Mr. Freeze's cell, allowing the blue-skinned man to finally attain freedom, collapsing onto the ground in front of Batman, who lifts his head up.

"Joker's cure. Where is it?"

Mr. Freeze scoffs at his question. "Forget the clown. I want Cobblepot. He has my suit, my weapons. I'll end him for what he's done to me." He says.

"Penguin's mine. You need to stay focused on that cure or innocent people will die." Batman says as Hulk enters the room.

"Nice work with the puny men, Bat." Hulk says as he looks at the unconscious henchmen. "Tougher than you look." He says as he looks down at Mr. Freeze. "Oof. Someone's having a bad day..."

"You don't understand, Batman. I cannot complete my work without my suit. I must have it. Everything depends on it. Everything."

"Penguin is protecting himself...with your ice gun. How do we get past it?" Batman asks.

Mr. Freeze 'coldly' chuckles at his question. "Do I look like a fool? Why would I tell you two that?"

"Grrrrr..." Hulk growls impatiently.

"Because if we can't get past it, we won't help get your suit back. Think about it, Victor. You don't look well. If you're gone...what'll happen to Nora?" Batman asks, knowing Freeze will take offense at that.

"Leave my wife out of this! Don't let this situation fool you and your friend. We are not allies."

Without skipping a beat, Batman pulls the coolant filled cylinder out of Freeze's chest, an action that even Hulk was surprised by.

"Geez...not even I'm that twisted..." Hulk says.

"Today is not a good day to push us, Victor." Batman says as he pours some of the coolant onto the floor.

"Stop! I'll help you!" Freeze says in protest, to which Batman stops pouring. "There's a security override chip...I built into the suit...to stop anyone using my..weapons against me." He says weakly.

"How did that work out for you?" Batman sarcastically asks, tilting his head.

"Why don't you two go get the security override, and figure out a way to stop him yourselves?" Freeze meanly asks.

"Hmmmm..." Hulk growls again as he walks away. "Jerk."

"Been a pleasure, Victor." Batman says, walking away before tossing the coolant cylinder back to Freeze, who implants it back into his body.

-Later-

Prehistoric Wing

With Hulk by his side, Batman heads to the wing where Freeze's suit is being kept behind a display case.

"That's the famous Freeze suit..." Tom Miller says in awe.

"Sure is." Hulk says as he punches out the glass, allowing Batman to pull out a strange vial and hand it to Tom.

"When we leave, get this over to Freeze. He won't be dangerous." Batman says as he pulls a small microchip out of the suit's forearm.

-Iceberg Lounge-

Hulk and Batman enter and after avoiding several streams of ice from the ice gun, use the security override chip on the ice gun, jamming it long enough for Batman to uppercut Penguin to a lower level of the Lounge. Hulk grins at Penguin's defeat.

"You're finished, Cobblepot." Batman says angrily.

"No! I'm sorry! Please, don't hurt me!" Penguin grovels.

"Ha! Begging now? Even for you, that's pathetic!" Hulk mockingly says.

"We can't guarantee you'll be unharmed, Penguin." Batman says.

"Hehehe! Me neither!" Penguin says as he whips out a detonator, blowing up the floor beneath the two heroes, leading them to fall into a dark chamber and groan upon hitting the ground hard. "I gave you two the opportunity to end this and walk away, but no. You boys had to act all big and tough. Well, guess what? From up here, you look pretty small." Penguin mocks as he presses a button, which activates some electrical equipment, illuminating the room. "Don't be so sad. I've got a surprise for you down there." Penguin says as the heroes spot a large, grey-skinned man bound by some chains.

"Don't tell me that's who I think it is." Hulk says as Penguin electrocutes the large man, making him spring to life.

"Solomon Grundy..." The large brute groans. "Born on a Monday...Christened on Tuesday...Married on Wednesday!" He roars.

"Found him down there when I bought the place. Hehehe! Comes in handy..." Penguin says as Grundy breaks free from his restraints, towering over the two heroes.

Grundy roars as he slams one of the chains downward, though the heroes dodge the attack, following it up by Hulk leaping up and punching Grundy across the face, and Batman slicing Grundy's leg with a batarang.

"How do we kill someone who's already dead, Bat?" Hulk asks as he punches Grundy again.

"Hit him hard!" That was all Batman could think of; he was too busy avoiding Grundy's attacks to think up a strategy.

Hulk rolls his eyes as he punches Grundy's knee, making him kneel down and allowing Hulk to repeatedly punch the giant zombie in the face, dazing him as he fell on both knees. Batman takes advantage of Grundy's vulnerability and along with Hulk, repeatedly punches Grundy in the head again and again.

Penguin growls in frustration as he presses a button, reactivating the electrical machine and charging Grundy up again.

"Raaahr!" Grundy roars as he swings his chain weapons at the heroes, who once again avoid his attacks and counter with much faster attacks of their own. Hulk takes point, punching and slamming into Grundy as if he was a walking battering ram.

"Die, Grundy!" Hulk roars out. "You're not so tough!" As he continues to pummel Grundy, Hulk notices his exposed heart, which was glowing a sickly yellow color. "I really wish I didn't have to do this..." Hulk mumbles to himself as he lunges at Grundy and punches his heart, making Grundy fall down dead...for good.

Right on cue, Penguin enters the chamber through a door, clutching a grenade launcher. "Oi! Just me now! The Bat and Beast vs the Bird!" He says as he starts to rapidly fire his weapon at the heroes, missing every time due to their superior speed. As Penguin frantically tries to reload his weapon, Hulk grabs the small man by the shoulder.

"I told you to shut up!" Hulk roars in Penguin's face before slamming on the ground, hard enough to take him down, but not enough to kill him.

-Later-

Now in his armored suit, Mr. Freeze looks at a female ninja being held in a display case near the entrance of the museum before turning around to look at Hulk and Batman, the former of which was holding Penguin by the throat.

"Where...is Cobblepot?" He asks as Hulk drops him in front of Mr. Freeze.

"Here he is. That little jerk..." Hulk mumbles.

"Well, look who it is. Mr. Free-!" Penguin screams as Mr. Freeze steps on his broken hand, clearly enjoying his screams of pain.

"Freeze! Enough!" Batman says in protest.

"Of course." Mr. Freeze politely says as he picks Penguin up and slams him against the ninja's display case, cracking it. "You will..regret what you did, Mr. Cobblepot." As Penguin groans, Mr. Freeze carries him to an empty display case and tosses him inside, locking him in.

"The cure, Freeze." Batman says.

"There...isn't one."

"What?!" Batman exclaims.

"What do you mean, baldy?" Hulk asks. "No cure? That's bull."

"Perhaps I should elaborate." Freeze says as he displays a 3-D hologram of the cure's formula. "Creating an antidote to the disease that afflicts the clown was easy. Unfortunately, the cure degrades too quickly. It needs a restorative element, some kind of...reforming enzyme. Without it, it breaks down...before it can help its host."

"I've seen this before..." Batman says as he looks at the hologram. Hulk, however, only tilts his head in confusion.

"Finding a suitable enzyme isn't the only problem. It needs to be adapted, bonded to human DNA. That will take decades, time it appears...you do not have, Batman."

This gives Batman an idea. "What if I told you I know a man that's been exposed to that enzyme for centuries?"

"Hmm? What man?" Freeze asks.

"His name is Rã's al Ghül." Batman answers, getting the ninja, who was now meditating to open her eyes and look at the trio.

"Bring him to me. All I need is a sample of his blood. It's your only hope."

"Rã's al Ghül is dead." Batman says in defeat.

"Crud." Hulk adds.

"Then you and the clown are doomed." Freeze says melodramatically.

"Not exactly. I just need someone to tell us where the body is...then we can wake him up." Batman says before looking at the ninja, who breaks out of her display case.

"Blasphemer! You are not worthy to speak of the great Rã's al Ghül!" She whines as she runs away, leaving a blood trail in her wake.

"Coward!" Hulk yells at her, though she's already long gone. "Urgh...I hate ninjas..." He mumbles.

"Batman, you fool. You let your only hope escape." Freeze says.

"Shove it, ice cube head." Hulk retorts to Freeze.

"No, Victor. If Rã's al Ghül is in Arkham City...we now have a trail right to him."

-Author's Note-

Sorry for the delay.

I can make the Grundy fight longer if you like.