After witnessing Killer Croc drag Scarecrow into the depths of the sewers to an unknown fate, Batman made sure to contact Oracle.
"Oracle, I'm heading into Croc's lair to collect the plant spores Ivy spoke about. He's in some kind of old sewer network. Send me the schematics, it's like a maze down here."
"There's nothing on record. Bruce, are you sure about this? Sounds like a suicide mission."
"I can detect the spores required to make the Anti-Venom." Penny said. "Ben and I will distract Croc while Batman collects the spores."
Normally, Batman would immediately shoot down this idea, but the two young heroes had kept surprising him at every turn. Besides, if they could handle Bane, he was sure they could handle Croc as well.
"You'll be in his element. Are you sure?" He asked them.
Ben smirked. "Bring it on."
Batman nodded at this. "Then get ready to fire."
The Dark Knight then bolted down the pathway, landing heavily on the wooden panels, sending his position to Croc. The monster lunged out of the water halfway onto the panel, attempting to grab Batman, only to be stabbed in the side by one of Penny's Floating Array blades.
"You reeled him in!" Ben said as he charged forward and held his hands out, causing the sewer water around to rise up and form solid water chains that shackled Croc as he struggled.
Letting out a primal roar of rage, Croc grabbed Ben and dragged him into the water with him, attempting to drown the Elemental only for Ben to release reverberating soundwaves that shook the water and caused Croc to let go of him, clutching his head in pain.
Ben swam back to the surface, Penny pulling him up. Croc then burst out, having recovered from Ben's sonic attack, only for Penny's eyes to blaze brightly with the power of the Winter Maiden as the air became colder, a veritable blizzard taking over and freezing the water as Croc began shivering.
"Looks like you're cold-blooded like a reptile too," Ben noted before punching his fists and creating a large prison of ice and snow that completely ensnared Croc.
Not completely without mercy, Ben put a small heat ball to keep the villain warm. He then dropped into the water, still imprisoned and suffering from hibernation reflexes but at least with the heat orb to keep him from suffering further ill-effects.
"That'll keep him napping for a while," Ben noted.
Penny giggled. "Well, he certainly wasn't so tough."
Soon, Batman came back to see all the action that went down and nodded his head to the two of them.
"Did you get enough of the plant?" Penny asked.
Batman nodded and held up a vial containing the anti-venom mold. With their objective complete, the trio traversed the sewer system and exited through the previously sealed door. They backtracked towards the vent leading to the Batcave, finding a number of thugs apparently searching for it as well.
Quickly, Batman attacked the high-security inmate with knives using a flying kick before spinning and hitting the thug to his right with a jumping left side kick. Penny fired her Floating Array in their laser blaster modes, sending the other thugs to the ground as Ben trapped them under miniature forces of pressure, keeping them pinned to the ground.
With the goons dealt with, the trio got to the vent, but before they climbed in, they felt the ground shaking violently all around them, to the point they almost struggled to stay on their feet.
"I take it you felt that?" Oracle asked.
"How could we not?" Ben sarcastically replied.
"The plants are going crazy. I'm getting seismic spikes in all locations. It's not good."
"It's okay. I've got the mold samples. I'm heading to the Batcave to mix up the antidote." Batman said.
"Good. I'd tell you to hurry, but I'm sure you know what you're doing. Contact me in the cave if you need anything."
"With our combined talents, this will be a breeze!" Penny said optimistically.
With that, the trio climbed through the vent and dropped back into the cave. They headed to the back entrance, where another scanner like the first from the other side awaited them.
"Scan and open."
It did as instructed and allowed Batman and his wards back into the Batcave, where they hurried to the main computer.
"Alright, what's the set-up?" Ben asked. "Think the antidote is any good?"
Batman frowned. "It's more difficult than I expected. The process is slow, difficult, and doesn't produce much antidote."
"I see..." Penny frowned. "What's the good news?"
"The chemical will definitely stop Ivy. It may also reverse the Titan transformation. I need to run more tests to be sure." Batman said as he took out a special injector filled with the antidote. "I've set the computer to make more, but we need to get out of here and find Ivy."
"Thank god. Her plants have reached the Gotham River." Oracle said, having been listening in as well.
Suddenly, massive vines bore in from the roof and tried to smash the heroes, but they quickly jumped out of the way. Batman even dived over the edge as Penny dodged and maneuvered to any safe place she could find where there weren't vines before catching Ben, who was about to fall, and carrying him to safety.
"Guys! Are you alright?!" Oracle asked worriedly.
"We're fine," Batman said as he pulled himself up to safety. Ben and Penny rejoined him, the android gently letting go of the elemental.
"Looks like Ivy's on to us..." Ben frowned.
Batman walked over to a desk and began upgrading his Batclaw gadget to have three hooks that could fire together and pull down heavier and larger objects. Using this he pulled down a weak wall, allowing him, Penny, and Ben to sneak out of the Batcave.
"This is quite dangerous," Penny said. "I understand that you are more than capable of handling things, but I cannot help but be worried."
Ben smiled. "Awww, I'm touched. You really are a peach, Penny."
"We don't have any other choice, Penny," Batman said.
Penny nodded. "I know, but...this idea came to me a while ago. Since I possess a soul and therefore an Aura...I could try using it to unlock yours as well."
"Wait...you mean like all that crazy Aura stuff from your home planet or whatever?" Ben asked. "Can that even work with us?"
"It won't hurt to try."
Penny held her hands out, gesturing for Batman and Ben to take them. The two obliged and closed their eyes as Penny's brilliant emerald-green aura shined brightly. A deep black glow surrounded Batman, and a shifting black and white glow surrounded Ben.
"For it is in passing that we achieve immortality. Through this, we become a paragon of virtue and glory to rise above all. Infinite in distance and unbound by death, I release your soul, and by my shoulder, protect thee." Penny recited before her glow faded and she backed up and hunched over a bit in tiredness.
"Penny!" Ben gasped as he moved to help her.
"Are you alright?" Batman asked, kneeling down to make sure the android maiden was alright.
"I'm fine...due to being an android, I have a strong aura reserve..." Penny smiled. "I just need to recover a little bit."
"I don't know what you did, but I feel...stronger, faster." Ben noted, clenching his fists. "Maybe this'll work out after all...fingers crossed."
Following the new path Batman had made earlier with the Ultra Batclaw, the trio arrived at a back entrance to the cave where a trail of of cliffs and plateaus led to another cave. Carefully maneuvering the treacherous path and avoiding the large rock pillars in the way here and there, the two eventually reached the entrance to the sewer system once again, retracing their steps almost until they reached the door leading to Croc's lair, but then turned the other way.
"Batman, I've been running a simulation of the damage Ivy's plants will do if they reach Gotham..." Oracle said.
"They won't get that far. My antidote will stop them and Ivy."
"We're busting out the Omega-level weed killer, that's for sure!" Ben said to Penny with a grin, making her giggle.
"Too true!"
They reached the main sewer junction but quickly discovered a new situation; a nasty green liquid was coming down like a waterfall from the upper levels.
"What in the name of Oum is all this?" Penny asked in shock.
Batman quickly called Oracle. "Oracle, we've got another problem."
"What now?! Two-Face? Riddler? Penguin? Some kind of giant Joker robot? POLKA-DOT MAN?!" Oracle asked, annoyed and almost in disbelief at the new problems constantly popping up all around.
"Huh, haven't heard from Riddler in a while, actually..." Ben realized. "Maybe our words to him from before scared him off."
"Unfortunately, nothing that simple," Batman replied to Oracle. "We're at the Main Sewer Junction and it appears to be polluted with Titan. Why? What's he doing now?"
With that, the two vigilantes continued to traverse the sewer system. Getting close enough to dip his hand into the substance, Batman came to a conclusion. Penny came to the same realization as she scanned the waters.
"The substance appears to be corrosive, but it shouldn't trouble my suit," Batman said. "I'm sure you and Ben can protect yourselves, right Penny?"
Penny nodded. "Indeed! My aura will protect me and my endoskeleton is impervious to most dangerous elements."
"Hey Oracle, what have you found out?" Ben called.
"I'm not sure the three of you are ready for this."
Ben frowned. "Maybe not, but go ahead."
"Joker is pumping all the waste product from the Titan process into that chamber. It acts as a kind of natural storage tank. Once it's full, it releases the water into the Gotham River. Normally, it's safe, but..."
"But this time it's full of Titan!" Penny gasped. "How do we stop it?"
"I'm working on it."
The trio quickly made their way to try and stop the waste production. Oracle guided them to three different rooms. Batman broke down a weakened wall with the Ultra Batclaw and Ben and Penny pounced on the unsuspecting thugs to knock them out.
"Helloooooo? Can you hear me?" Joker asked over the TV, sighing when no response came. "Oh, for the love of... I suppose that's you down there, Bats and Friends! Well, enjoy it while you can. These caves will be your tomb."
"Does it look like we're scared?" Ben asked with a glare.
The trio proceeded down the hallway and into the next room, finding a couple of thugs at the top of the stairs in front of them with their backs to them. Batman pulled out his Batclaw again and looked at Ben and Penny, who nodded. He caught and reeled in the thugs, pulling them to the ground and stunning them, allowing the Vigilantes to jump on top of them, pin them, and knock them out with a ground takedown.
They soon reached the center of their room and checked their maps once again, finding two indicators for the control rooms down different paths, then looked at each other.
"Alright, Batman takes one path, me and Penny take the other path." Ben noted.
Batman nodded. "Be safe, both of you."
Batman took the right path while Penny and Ben took the left.
(Batman)
Hurrying down this path and entering the control room, the Dark Knight pulled out a batarang and threw it at a thug just passing the entrance. Quickly and silently moving over, he reached the downed thug and knocked him out with a Ground Takedown, then grappled to a gargoyle behind him in case any thug became aware of the sound. He then grappled to the gargoyle in the center of the room and threw a batarang at a thug to the left of the generator-looking device in the middle of the room, knocking him down before the Dark Knight dropped down on his and took him out with a Ground Takedown as well.
The first thug's suicide collar went off at that moment, though, getting the attention of the other thugs, and forcing Batman to grapple to yet another gargoyle.
"Batman's been busy! Didn't you notice that some of your crew is missing down there!?" Joker demanded.
Batman threw another batarang from here at a thug to the far left of the room, sending him to the ground for another takedown, then ascending back to the gargoyles. A pair of thugs found the first one of their comrades Batman had knocked out in the middle of the room, their attention focused on him and not the fact they were an easy target as Batman threw two batarangs and knocked them both down, quickly gliding over and taking them out one right after the other.
Another thug rushed in to check out the situation and was shocked when he made it halfway there and already saw the unconscious bodies of two of his allies.
"C'mon, where are you? Ah, to hell with this!" He snapped, looking around for Batman, not noticing yet another batarang flying through the air and blindsiding him, hitting him in the face and sending him to the ground, where he too was taken out.
"He's taken one of you out! And not in a nice first date kind of way! You better not let him shut off the pipes! Or else I'll throw you in that corrosive goo that's supposed to melt Gotham!" Joker barked furiously at the last remaining thug in the room with the control panel.
"Ahh, screw this! I'm staying right in here! There's only one way Batman can come through to get me: right through that door..." The thug said confidently as he readied his rifle at the door, waiting for Batman to step through so he could shoot him... all the while the Dark Knight had casually walked down the stairs below the room the thug was in, almost in a bored manner as he readied his Batclaw to tear down the weak floor the thug stood on.
"C'mon, Batman... I'm waiting for ya... Any minute now..." The thug said, before screaming as the very ground came out from underneath him, causing him to fall on his head and knock himself out.
"I said I wanted the Bat stopped! Did no one listen?! It's like you almost don't want an outbreak of Titan-enhanced mutant babies climbing over Gotham!" Joker said as Batman used his Cryptographic Sequencer to destroy the terminal and stop the flow of Titan.
"Oracle, I disabled Pump #3. How are Penny and Ben doing?" Batman said.
"Great work. they finished up theirs a minute or two ago and are making their way back to the center room."
(Penny and Ben)
Penny and Ben had taken the left path and reached the next room at the top of the stairs, entering it. Using her scanner, she found she was on an upper level above seven thugs, only one of them armed with a gun. She sent out a thunderbolt with her Winter Maiden powers, taking him down, before jumping down into the crowd of thugs, landing right in between three of them, punching away.
"It's the robot and the punk! Get 'em!"
Penny punched one in the face and used her Floating Array to push him into the wall and knock him out before launching her arm back, causing her to smash her elbow into the heads of one of the thugs behind her, then uppercut the third one of the trio she landed between.
Two more thugs came at her, one with a lead pipe, but Ben fired a burst of air that stunned the pipe-wielding thug, causing him to hit the other thug in the face and make him stagger around, holding his face in pain, until he walked into the path of one of the pistons at the sides of the room, getting hit and thrown into a wall at high speeds, getting knocked out as Ben uppercut the thug with the pipe, knocking him out.
"They're making you look stupid! Which admittedly isn't very difficult, but it is NOT why I put you down there! They're trying to shut off the pumps! Don't let them! Is that clear?! You want me to send Harley... Oh, damn, she's locked up... Do you want ME to come down there!?" Joker snapped.
"Sorry, Joker! But your method of acting isn't very clever!" Penny taunted as she unleashed the full power of her Winter Maiden powers, freezing the remaining thugs in place.
Penny then approached the control panel and flipped open the tip of her index finger, revealing a special key that she used to hack it, disabling the pumps as Ben smashed the other one.
"Easy peasy."
The two then headed back to regroup with Batman at the spot where they had to split. However, just as they were about to leave, security gates suddenly went up, blocking any path they could take.
"Get ready for whatever Joker's got planned now. He's getting angry." Batman said.
"Just what we needed, an ANGRY Joker." Ben frowned.
"I know you're down there, Bats! And you're new sidekicks too! Ruining my plans... Well, stay where you are! I'm sending down a token of my displeasure. Oh gosh, I hope it doesn't hurt you too badly." Joker said, in a fake worried tone.
Suddenly, a Titan came crashing down one of the elevator shafts, roaring and charging at our heroes.
Batman threw a batarang at its face, causing it to charge blindly, completely missing the three as they dove out of the way and making it crash into an elevator full of thugs that had just opened, knocking out most of the thugs in the process. The three of them moved in and prepared to attack before the other two elevators opened to reveal about eight more thugs for the vigilantes to deal with.
"Oh, come on! One issue at a time!" Ben said, deflecting a pipe and punching its wielder in the face with a metal fist, kicking back another thug and countering another's punch, sending it into the face of one of his allies, allowing him to jump and send out blasts of smoke that sent them to the ground before throwing a bubble at another thug with punches that exploded with the force of a flashbang.
Batman had intentionally gotten surrounded on all sides by his small group of thugs, but suddenly flipped out of the way, leaving explosive gel behind, which he quickly detonated, taking all the thugs off their feet and launching them a few feet away. They attempted to get up, but Batman quickly put a stop to that by throwing batarangs at their faces and knocking them out before they could get up.
Penny had decided to tangle with the Titan Thug, using her Floating Array blades to cut it up in certain areas, making it flail in pain before she used the strings to bind its legs together, making it fall to the ground hard. Before the Titan thug could get up, Penny formed green flames over her fist and punched its head hard enough to knock it unconscious with a single blow.
"We are unstoppable!" Ben cheered as he scooped up Penny in a big hug, making her laugh and blush at the same time.
"Easy, you two. We're not finished yet." Batman said, though there was a small smile on his face.
Ben awkwardly set Penny back down as they followed after the Caped Crusader. They had stopped the Titan waste disposal, now it was time to refocus their efforts on Poison Ivy.
First, it's time to take down Poison Ivy, then it's time to go after Joker!