In DC universe as Batman

"You're going to help me. Otherwise, this world's fragile peace is finished."

Harley Quinn rolled her eyes.

"Oh sure, because Bane, Joker, and Two-Face are such peaceful little angels. Maybe go deal with them first?"

"I have plans for them," Bruce said coldly. "You don't need to worry."

"Anyway," he added, "even a lunatic like you still values staying alive."

Harley grinned and leaned in.

"Well, since you put it that way... how about a little sweetness to seal the deal? Spa day for me. And a signed photo for my cousin—he's sick and totally obsessed with you."

Bruce said nothing. He walked past her and around to the other side of the Batmobile.

He counted silently in his head:

3…

"Hey, Bat! Only I can…"

2…

"Bat? Batman?"

1.

"Fine, whatever. You're the boss."

Harley threw her hands up and hopped into the passenger seat.

Tim Drake—the third Robin—watched in disbelief, scratching his head.

"…Wait, Harley Quinn's coming with us?"

He moved in front of Bruce.

"Is this actually a good idea?"

"Not my first choice," Bruce replied. "But we can't take our eyes off her. She could warn Poison Ivy we're coming."

"Ha! That's right!" Harley said cheerfully, pulling a silly cross-eyed face and jabbing her fingers at her temples.

"The dangerous lunatic is right here! No one knows what I might do!"

The trio loaded into the Batmobile.

"Harley," Batman said, "I just need you to help us find Ivy. That's it. We'll handle the rest."

He sat behind the wheel and pretended to drive it, though the AI handled the actual driving.

"We're making a stop first. Then we go after Ivy."

"Okaaay," Harley said, drawing out the word. "So what's Ivy even trying to do this time?"

"Considering the recent attacks on STAR Labs and the Joint Institute for Advanced Superhumans, and factoring in the involvement of Professor Goldblum and Plant Master," Bruce said, "I've concluded they're engineering a swamp-based biovirus."

"They're planning to mutate it—turn it into a contagious form that rewrites human biology. A fast-spreading plague that converts people into plant-animal hybrids. Then they'll 'cleanse' the Earth."

"Ugh, gross!" Harley gagged, stretching her neck dramatically.

"Dont get me wrong, I'm not some kind of racist—some of my best friends are plants, you know!"

"Well, at least they're not trying to kill everyone," Tim offered.

"Maybe," Bruce said, "but if they succeed, humanity's finished. We'll be overrun by mindless, half-sentient vegetation."

He glanced at Harley and added,

"And if the formula mutates even slightly, we're looking at total biosphere collapse within days."

"Wow," Harley said, blinking. "That's so motivating."

Tim frowned.

"But why do they need Goldblum? Why not just spread the virus themselves?"

He answered his own question before Bruce could.

"They want a shortcut. True genetic rewiring could take decades. Ivy's a natural mutant. Plant Master's not even human -- he is some kind of interdimensional tree spirit. But for mass conversion, they need a scientist."

"Tree spirits from another dimension?" Harley mocked. "Come on."

"You've seen Clayface. Killer Croc. You know this isn't even the weirdest part," Bruce replied.

"Forget it," he said, ending the conversation. "Just help us find Ivy."

The Batmobile slowed to a stop outside a decaying apartment building.

---

Meanwhile, deep in Massacre Swamp…

Inside a rickety wooden cabin filled with lab gear, strange monitors, and overgrown vines:

mua~

Poison Ivy kissed Professor Goldblum. Passionately.

"Oh god, this is so disgusting." muttered Plant Master, turning away with theatrical disgust.

The leafy entity stood by the window, arms crossed, branches creaking with annoyance. His bark-covered body glowed with faint green pulses, and his pointed ears twitched with every smack of Ivy's lips.

The kiss finally ended.

Goldblum's eyes glowed an unnatural green. He stumbled forward like a hypnotized zombie and began preparing chemicals at the lab bench.

"Do you think I enjoy swapping spit with him every six hours?" Ivy snapped, wiping her mouth and spitting on the floor.

"If you have a better way to keep him under control, feel free to share."

"Tsk." Plant Master shrugged.

"Life's full of hardships."

"Well, I don't want hardships," Ivy hissed.

"Fine. Then we'll give them to someone else. 8 billion of them."

"No, not hardship. Purification," Ivy corrected. "We're cleansing the planet. Our mission is noble. Righteous."

"Hah. Noble and righteous. Words invented by apes with delusions of godhood," Plant Master sneered.

"They kill species by the dozen, burn forests for fun, and poison the oceans—then cry about 'climate change' like it wasn't their fault."

"It is their fault," Ivy nodded. "They don't act until we force them to."

That shared conviction solidified their alliance.

They both turned to Goldblum, who stood over a blueprint of their plan.

"Once our virus is activated," Ivy said with quiet awe, "the whole planet will be reborn. A lush Green paradise."

Goldblum opened a cage and lifted a white lab mouse. His gloved hands held a syringe filled with luminescent green liquid.

"Okay, little guy... just a little pressure. You'll be fine."

He injected the mouse.

Under their watchful eyes, the creature began to glow. Its fur turned mossy green. Tiny leaves unfurled across its back. Its tail twisted into a vine.

"Success!" Plant Master cried, elated.

"It's stable! Look at him—he's perfect!"

"Come to mommy," Ivy cooed, cradling the leafy rodent in her palm.

"This is no ordinary green mouse," Plant Master declared, raising his hands.

"This is the harbinger of a new era! Humanity's machines will fall. Nature will rise. Cities will become—"

SPLAT.

The mouse exploded in Ivy's hand, spraying her and Plant Master with a warm, sticky mass of green sludge.

Silence.

"...Okay," Ivy muttered flatly, flicking goo from her face.

"Maybe one more trial."