Batman scans the floor, spotting some blood that undoubtedly belonged to the assassin. After scanning it, Batman calls up Oracle. "Oracle, change of plans. We're going after the League of Assassins."

"What? Why? What have they got to do with all this? Wait a minute. Is this about Rã's...or his daughter?" Oracle asks, piecing together a possible reason as to why Batman all of a sudden wants to focus on the League.

"Penguin had one of the League's assassins imprisoned in the museum. I recognized the insignia. She's a member of Talia's elite guard." Batman says as he and Hulk slowly walk upstairs, heading for the entrance.

"I knew it. Bruce, what is it about that woman that makes her the most important person in your world?" Oracle asks in a rather jealous sounding manner.

"Hmph. Jealous much?" Hulk jokingly asks, listening in on the conversation.

"Talia is not the goal, Barbara. I've uploaded Freeze's unfinished cure. It looks to me like the answer is-" Batman says, only to be cut off by Oracle.

"Found in Rã's al Ghül's blood. Okay, Bruce. I guess you guys need to go after him. But please stay focused. Don't let her get in the way again." Oracle pleads as Batman ends the call.

"This isn't awkward at all..." Hulk lowly says.

"I agree it's an odd feeling, but we have no choice. Rã's blood is the only hope I have, as well as Joker and anyone else he poisoned." Batman says in response as they exit the museum. As Batman says this, Hulk grunts and nods in response.

-The Bowery-

As the two start to investigate where the ninja might've gone, they eventually spot blood. Batman scans it and realizes it's the assassin's blood and motions Hulk to follow him as the search is led to the rooftops. As they continue to follow the trail, they come across some blood soaked bandages, of which the blood matched the assassin's. Noticing Batman stop, Hulk starts to wonder. "What is it?"

"The blood trail stops here." Batman says before the two get blindsided by the assassin. Ever since Hulk joined Batman's side, the League has started coating their weapons in adamantium, which is durable and sharp enough to pierce even Hulk's dense hide. As the two recover, Batman spots the ninja hopping across the rooftops. "The only way to find Rã's is to get a tracker on that ninja!"

Hulk grunts and nods. "Got it!" He then runs after the ninja with Batman following behind him. After hopping several buildings, the ninja stands still on a large rooftop as Hulk lands in front of her and swings his right arm, only for the woman to flip over his attack and slash the back of his legs with her sword, green blood pouring from the deep cuts as Batman glides down and trades blows with the ninja before sneakily attaching a tracker to the back of her shoulder. Once he does this, the ninja knocks him down and pins him while two other ninjas surround Hulk, their swords pointed at him.

"You both only live because the great Rã's al Ghül commands it!" The first ninja says before hearing a whistle as her allies are quickly knocked out by a hooded figure wielding a bo staff.

As Hulk heals, he smiles, recognizing the 'R' on the figure's chest. "What're the odds...?"

"Call him off!" The ninja says as she presses her blade to Batman's throat. The hooded man tightens the grip on his bo as he approaches Batman's foe.

"I can take her." The figure says.

"Stand down." Batman says calmly. As much as the hooded figure didn't want to, he listened and distended his weapon.

"Do not follow us." The ninja says softly as she gets off of Batman, sheathes her sword, and runs away.

"Coward..." Hulk grumbles as he slowly stands up. "Nice to see you, Robin."

"You too, green." Robin says with a light smile.

"We didn't need your help." Batman says pridefully.

"Really? That's not how it looked from where I was standing." Robin remarks.

"We had it under control. Why did Alfred send you?" Batman asks.

"He was worried about you." Robin answers.

Batman says nothing as he pulls an unmarked vial of blood from his utility belt and hands it to Robin. "Take this and get it analyzed. Start searching the hospitals and emergency rooms throughout Gotham. Anyone with this blood in them will be dead within 24 hours."

"Whose blood is it?" Robin asks before thinking it over. "Oh...it's yours, isn't it?" He asks, not getting an audible answer from Batman. "I'll get it to the hospitals and come back. You guys need my help here."

"No. We can handle it. You're needed in Gotham. Things could get worse. Much worse." Batman says.

"You think? If Strange really knows who you guys are, what happens if he tells everyone?" Robin asks Batman, who puts his hands on Robin's shoulders in an assuring way.

"Trust me. We'll find a way." Batman says.

Robin nods as he hands Batman his Line Launcher and begins to walk away. "If you guys need me, you know where I am."

-Later-

Amusement Mile

After Robin leaves for Gotham, Hulk and Batman traverse Arkham City, following the signal of the tracker Batman put on the League ninja, leading them underground as Batman contacts Oracle. "Oracle, we're heading underground. Below the surface, Gotham's a maze of old steel and ironwork. Our signals might get weak. Try to stay locked on."

"Got it. Re-routing additional satellite coverage now. Good luck, guys." Oracle says to them.

-Later-

As the two heroes wander through some underground buildings, Batman suddenly falls to his knees as Hulk stands over him with concern. "Batman?" Hulk asks, wondering about his friend's wellbeing as Oracle chimes in.

"Bruce! Are you alright? Did something happen? All the readings from your suit just went red." She says to Batman, who struggles to stand as Hulk helps him up.

"Just...give me a minute. I'll be alright." Batman groans as he coughs.

"No, you won't, Bruce. Hurry! You're running out of time!" Oracle says, clearly worried about Batman.

"She has a point, Bat." Hulk says, overhearing what Oracle said.

-Later-

After regaining his strength, Batman and Hulk continue on, eventually coming across some of Joker's men, who have somehow gotten their hands on weapons used by the TYGER guards, which was very concerning for Batman. Hulk, however, simply cracks his knuckles and leaps into the building they're standing in, and quickly takes them down with hard, but controlled punches to their faces and torsos, knocking them out. After the goons pass out, Batman contacts Oracle again. "Oracle, looks like Joker is sending his crew down to steal weapons off the TYGER guards."

"That's not good. Those guys are armed with the latest military weapons. If Joker gets his hands on that stuff...Well, you know." Oracle says with worry in her voice.

"He won't. We won't let him." Batman says as he ends the call.

"Even if Joker gets them, they'll be useless on me." Hulk says boastfully, pointing out that he's bulletproof.

"Not all of us are immune to bullets, Hulk..." Batman remarks.

-Prince Manor-

Diana stands by the window of her bedroom, worrying nonstop about Hulk, even though she knew he could take care of himself. As she stares off into the distance, baby Atreus coos, "Dada."

"I know you miss your father, Atreus. As do I." Diana says softly as she lifts her infant son up and cradles him in her arms. "I worry for him. Even when it's unnecessary. I pray to the gods that he returns unharmed..."

-Arkham City-

Entrance to Wonder City

Cut back to Hulk and Batman, who enter a room, spotting a pretty nurse being held captive by several of Joker's men, who had TYGER guard weaponry, though it was nothing against the heroes' superior skills. After taking out the goons, Hulk holds the nurse in his arms as he leaps up to a higher level and sets her down. "Thank you!" The nurse, Fiona Wilson, says in gratitude.

"What are you doing in Arkham City?" Batman asks.

"Wait. I'm in Arkham City? What the hell am I doing here? I was grabbed outside the hospital I intern at. They must've drugged me. I woke up in a building up there." Fiona says, shocked to know where she was.

"The person in charge here has been rounding up doctors to try to fix Joker. Looks like you were unlucky." Batman says.

"He's dying, right?" Fiona asks the caped crusader.

"Seems that way." Batman replies.

"Is it...wrong not to feel bad about that?" Fiona asks.

"Maybe a bit..." Hulk mumbles to himself, crossing his arms.

"You need to stay here. Keep out of sight, and you'll be fine. We'll be back." Batman says to Fiona. As the two heroes continue to progress, Batman rings up Oracle again. "Oracle, it's us. Joker's not stealing the weapons from Strange. Strange is giving Joker the weapons."

"Are you sure? Pfft. Of course you're sure. Why would he do that?" Oracle asks.

"Maybe he's trying to control who runs the streets. We're going to look into it." Batman says.

"Okay, but..shouldn't you guys find Rã's first?" Oracle asks.

"That's what we're doing now. Don't worry, Barbara." Batman says, ending the call as he and Hulk come across a door down below with a sign above it that reads, "Wonder City".

"Wonder City. Never heard of it." Hulk says as he reads the sign aloud.

"This must be a secret place nobody's heard of. Maybe Rã's is using it as a hideout." Batman says as the two walk through the door. Once inside, they come across another door marked, "Welcome to Wonder City". As they enter, a mysterious announcer is heard.

"The world is doomed. Cities like Gotham will grow to resemble hell breaking through the sidewalk, continuing up into the sky." The voice says as Batman collapses again, this time coughing up his own blood as his vision begins to blur. He was running out of time.

"Batman!" Hulk says loudly as he leans down, concerned about his friend again as the voice continued to speak.

"Structures will grow to blot out the sun, and the people who live in them will be choked by the pollution they create. Eventually, when no space remains, this world will die, struggling for breath as man's mistakes nail the coffin shut. But...this doesn't have to be your future, Gotham." The voice says as Batman regains enough strength to stand and fire his Remote Electrical Charge at a generator in the floor, opening the door, revealing a staggering inmate.

"They're...everywhere..." The man groans as he falls forward, a dagger jutting out of his back, clearly the handiwork of a League ninja. As the two enter another room, three League ninjas appear and attack the duo, out maneuvering them and swinging their swords at them. As Hulk fights one, the ninja avoids a swing from his right arm and slashes Hulk's eyes with her adamantium-edged sword, making him roar in pain as he covers his eyes with one hand while blindly swinging at the ninja with his other hand, hitting nothing but air, though he quickly recovers from the wound and kicks the ninja into a wall when she lunges at him. Hulk then grabs another ninja and tosses it at the last one, who was swinging her sword wildly at Batman. With their foes defeated, they press on.

-Wonder City-

The two enter a long hallway, which is filled with buildings and glass cases, some of which have strange robots inside while others are lying around on the floor. "This place is weird..." Hulk mumbles as his eyes scan the area. Upon reaching a large door with a glowing centerpiece and an ornate decoration resembling a demonic face with red eyes, the two stop in their tracks.

"The tracker's signal continues beyond this door, but the door looks like it's been sealed for decades. The assassins must be using another way to get through." Batman says as he looks at the mysterious door.

"Then we better get through..." Hulk says as he starts punching the massive door, breaking through it with ease.

As the two heroes walk through the massive hole that used to be a door, Batman collapses once again, laying on his stomach and was unable to move, even as Hulk shook him. Soon after, Batman saw a gate slowly open, revealing a bright white light and the sound of his parents, who were beckoning him.

"Bruce...you can hear me, can't you?" Martha Wayne asks, her voice echoing through Batman's mind as he slowly looks at her, though to Hulk, nothing was happening. "You need to step into the light. Your father and I are waiting. We've missed you so much." Martha adds.

"Join us, son. Your time has come. Come with us." Thomas Wayne says as he and Martha hold their hands out to him.

"You have to do it. We need you to do it, Bruce. Bruce?" Martha beckons again as Oracle's voice replaces hers.

"Bruce! Bruce, can you hear me? Your vitals...they're dropping; it's like they're in freefall. You need to find whatever you guys are looking for now." Oracle says with distress as Hulk helps Batman stand up.

As Batman coughs, he asks, "How long have I got?"

"Oh, thank God." Oracle says in relief at hearing Batman's voice. "Um, I'm not going to sugar coat it, but at this rate...I'd say minutes. Seriously, you need to tell me what you want me to do. What do I get Robin or Hulk to do? You know, if you don't..."

"I'll make it." Batman weakly says as he ends the call.

As Batman weakly walks towards a door, with Hulk by his side, he falls onto one knee as several League ninjas surround them, swords drawn. "You fools should've listened to my warning."

"Just shut up!" Hulk says in annoyance as he gets ready for a fight. Before the ninjas can strike, however, a firm yet feminine voice calls out.

"Stop!" The voice calls out, prompting the ninjas to stand down. As Barman stands, a rather beautiful woman slowly approaches the caped crusader and rather harshly slaps him across the face.

"Hello, Talia." Batman smoothly says.

"Still holding a grudge..." Hulk mutters in response to Talia's slap.

"How did you find us?" Talia asks rather angrily.

"We recognized your personal guard. It was just a matter of...following her." Batman says as he presses a button on his wrist device, activating the tracker he placed on the ninja.

As Talia approaches the rather incompetent ninja, she gulps. "Please, mistress, they tricked me-"

"Leave. I will deal with you later." Talia says, making the ninjas bow and quickly depart, leaving Talia alone with the heroes. "You didn't need to get yourself arrested to see me, Bruce." She says as she looks at Batman, then looks upon Hulk. "Hulk. I'm surprised you're here as well...considering our history."

"I'm not here to reminisce on our past." Hulk says with a light smirk as he crosses his arms. "Though it was fun kicking your ass all those years ago..." He adds.

Talia chuckles softly. "I'd imagine not, old friend." She says. "My defeat in battle against you was more humiliating than fun." She adds before looking at Batman again. "Bruce...after that night we spent in Metropolis...you could've just called." She says to the caped crusader.

"I'm not here for you, Talia." Batman says. "Where's Rã's? If he's dead again, you need to wake him up."

"Only a true successor may stand before the great Rã's al Ghül. Care to volunteer once again, Hulk?" Talia asks.

"Tempting...but I was king before. Didn't go well, remember?" Hulk says, remembering his time on Sakaar.

"As you wish. Bruce...my father always intended us to be together...to command his army." She says to Batman as she starts to circle the caped crusader, placing her hand on his back. "Just imagine it. You...Me...A better world..." She whispers seductively as she lifts his cowl to kiss him, only to see that his face was greatly disfigured; his skin was turning a sickly white, and dark, visible veins could be seen all over. "Your face! What happened?" Talia asks, horrified by what she saw.

"That's why we're here. I'm here to take my place at your side." Batman says as he pulls his cowl back down, covering his face.

"You now wish to become an assassin? Why should I trust this change of heart?" Talia asks in disbelief.

"Uh...did you not see his face?" Hulk remarks to her questioning.

"Like he said, Talia, you saw my face. Does it look like I have a choice?" Batman adds.

"Are you truly prepared to take the Demon Trials? You must show you are fully willing to take a life to save the world." Talia says.

Batman nods ever so slightly and says, "I'm ready."

"Then let the trials commence." Talia says with a smile.