Minor spoilers for Season 2 and 3, but you can read this without watching any of the seasons.
Marinette really hadn't wanted the day to go like this.
Chat Noir wasn't supposed to be bruised up, gasping for just a little whiff of air as an Akuma slowly suffocated him.
Marinette wasn't supposed to be trapped in civilian form, armed only with a few pieces of junk strewn around.
But here she was.
It had started as a normal day, strolling underneath the Eiffel Tower, window-shopping the goods at the mini-market opened up that day.
Marinette had just passed a cart that was selling pieces of jewelry that matched the Miraculous, purchasing a pair of Ladybug earrings for Alya. She was going through the little bag she had brought along, looking at all the fabrics, thread, and little goodies she had brought when she heard the unmistakable sound of a crash.
Whipping around, she got to see the last moments of the Northern support beam of the Eiffel Tower be destroyed. With a sickening screech of metal, the leg broke, crumbling down on the opposite side of the market.
The poor people…they could be crushed!
Marinette was about to release Tikki and risk everything by transforming then and there, but Chat Noir suddenly appeared.
Even at her long distance from her, she could see Chat Noir's baton flash out, stretching from building to building on opposite sides of the streets, stopping the leg to crush the people below it.
"Get out of here!" He ordered the entire crowd, his eyes sweeping over the fair. "Go home, all of you!"
The crowd heeded his demands, except for Marinette and one or two stragglers.
Before she could run for a safe spot to transform, she caught her first look of an akuma.
It was obviously a middle-aged male, but besides that it was hard to get details. His entire body was constantly a swirling mess, looking almost like grey syrup.
Chat Noir, a few yards away from the victim with his back turned, was freeing his staff from the Eiffel Tower's leg. Fortunately for him, the entire landmark refused to collapse, despite only standing on three supports.
But then the akumatized man was there.
Before Chat even knew someone was behind him, the akuma's first morphed in something that looked suspiciously like concrete, smashing into Chat Noir's skull.
Chat Noir dropped all four floors on the building, not managing to land on his feet, but practically belly-flopped.
Nonetheless. He standing again, somewhat shakily, within three seconds, using his staff as a crutch.
The few remaining people had already fled.
Marinette didn't have to be close to know that they were right to do so; this would be a tough fight.
Getting to cover would be easy. There were some bunkers build underneath big landmarks, such as the Louvre, the Lock Bridge, and, of course, the Eiffel Tower. They were specifically crafted for akumas, with no wi-fi and screens, in case of akumas like Prime Queen and Lady Wi-fi, and the walls were a mix of concrete, iron, and steel to avoid strong villains like Weredad, Grozilla, and Gigantuar.
They weren't done quiet yet, since they still needed to be reinforced, but they were a perfect place to rapidly be able to transform in without being spotted.
Marinette entered an empty facility, one of the mostly-completed ones, and opened up her purse.
That was the moment when Chat Noir crashed through the ceiling, rubble and metal poles crashing down around him.
"Gaaah!" Chat cried, wincing as a chunk of concrete landed on his chest.
I'll make sure to tell the construction works that the roofs aren't strong enough. Marinette told herself, stepping back from Chat Noir. "Are you okay?"
"Marinette?" Chat Noir tipped his head back weakly as he shoved off the concrete, eyes widening in horror. "No, no! You need to get out of here! He'll be here any-!"
The akumatized man crashed down before he could finish, ripping apart the last of the ceiling, a particularly big chunk ending up blocking the door out.
"Never mind." Chat hissed, leaping to his feet ungracefully. "Stay behind me."
Marinette nodded dully, frowning to herself. Chat was pretty weak, she noted, concerned. The akuma has already given him quite a beating. He was lacking the gusto he usually worked with, his entire form shaking.
"What are you protecting, you mangy cat?" The akumatized victim cackled, trying to get a good look at Marinette. "Allow me to see."
"Just. You. Try." Chat growled, tail lashing behind him.
"Gladly." The man's arm turning into the grey syrup once again, lashing out in one movement.
Marinette couldn't even blink before he had Chat firmly by the neck, a smug grin on his face. The man pulled Chat forward, forcing him to his knees in submission. His eyes flickered to Marinette, looking at her in satisfaction. "Ah. So that's it. A girl."
"Don't touch her!" Chat screamed, pulling at the akuma's fingers.
"I'm sick of people telling me what to do!" The akuma roared, tightening his grip on Chat. "I was a scientist, performing experiments on the earth's mantel and core, namely the plastic rock deep within! But every successful experiment that I brought back was discarded, tossed aside as if it was worthless! But I know that all my theories were right, I knew my experiments were correct! For my stubbornness, I was fired. No one can ever tell Plastic Rock what to do now!"
Chat gagged, shaking even more then before. "P-please…don't d-do th…is…pl-please…please…"
Plastic Rock roared, loud and angry. "Don't tell me what to do!" His arm flung Chat into the wall, his rage enveloping him.
The blood-curdling scream that tore itself from Chat's throat tore at Marinette's heart, the girl letting out a cry of terror as she covered her ears.
Then Plastic Rock smashed him into the floor, each impact creating a huge indent in the walls.
Marinette reminded herself to tell the construction company that everything needed work on.
"Apologize!" Plastic Rock roared, glaring at Chat through narrowed, gold eyes.
Marinette's heart squeezed in pain, lowering her head.
Her eyes landed on a shattered tea cup, and her eyes widened in surprise, a smile beginning to light up her face.
"N-never…" Chat Noir's meek voice growled, followed by another scream as Plastic Rock slammed him into the opposite wall as before.
Marinette did her best to ignore Chat. Instead, she paid attention to the tea cup, realizing with a sudden avid feeling. If a tea cup somehow ended up down here, I wonder if any other piece of junk I can use is here, too.
First thing she noticed was Chat's staff peeking out from underneath Plastic Rock's foot.
That wouldn't help her. Next she spotted two hats, which still were worthless. She saw a hotdog, a stuffed animal alligator, and a-
Oooooh, that would definitely help her.
Marinette eyes flickered to Plastic Rock, to test if he was still distracted. He was, but…
Chat Noir was slowly being suffocated, his mouth opened wide as he struggled against the fist clamped around his throat, chasing off all his air. His skin was red, slowly fading to a dark purple.
Marinette risked the three steps over to the green and orange yo-yo laying in the rubble, scooping it up swiftly.
It didn't have the same perfect weight as Ladybug's yo-yo, but it would have to do.
Unwinding an inch of the thread, she hooked it tightly to her finger and began making it swing in a speedy circle around her hand, moving quicker and quicker around her hand.
She took up the battle pose she used so often as Ladybug, preparing to use the weapon to smack Plastic Rock upside the head.
"Hey, ugly!" She cried, aiming to provoke Plastic Rock. "Forgot about me?"
Chat Noir's half-closed eyes widened in horror and he numbly shook his head, trying to get her to back off.
"Ah, yes, the girl." Plastic Rock purred, forcing back his surprise at forgetting about her. "What's with the yo-yo? Do you think you're Ladybug?"
Marinette, knowing that if she answered would become a flustered, stammering mess, didn't bother to give him a reply, instead taking several bold steps up to him, letting her weapon hit him square across the jaw.
Plastic Rock stumbled backward in surprise, accidentally kicking Chat's baton over to Marinette while he also released Chat Noir.
Chat Noir collapsed onto the ground, coughing as he summoned as much air as he could back into his lungs, chest heaving.
Mariette ignored the baton at her feet, choosing instead to unleash all of her fury upon Plastic Rock, yo-yo hitting him with deadly accuracy between the eyes. She flashed one of her winning smiles as he groaned, his golden eyes glaring at her in fury.
Then her yo-yo struck again. While this toy didn't have the near-infinity reach that her magical one did, it had two meters of string connecting it to her hand, which made it plenty long enough to whip Plastic Rock.
It was then that Marinette noticed Plastic Rock's clenched first that never opened, much like Stoneheart's. His akumatized object must be within his hand.
By this point, Chat Noir had caught his breath, looking at Marinette in a mix of terror and surprise. He clearly was recognizing Ladybug's style in fighting, but he had yet to put two and two together.
Marinette's yo-yo dropped onto Chat Noir's baton, the extra weight forcing it to bounce in the air. She caught it with one hand, since she was using her other hand to charge up her yo-yo for another powerful attack.
She tossed the staff to Chat Noir, the hero catching it with professional ease.
Marinette used her yo-yo one more time to tie around Plastic Rock's hand, throwing her weight backward roughly, pulling him towards her. Chat's staff extended in his path, causing the akumatized victim to trip and fall, surprise in his face.
Marinette inwardly thanked God that he hasn't turned to liquid during the entire attack. He might be science-smart, but he certainly wasn't filled with common sense.
His hand holding the akumatized object - a round stone - opened in surprise by the two teenager's surprise attack.
Marinette dove for it, holding it to her breast. The dive turned into a roll towards Chat Noir, and she unlocked herself from the position as soon as she was close to him, standing briskly.
Chat Noir wrapped one hand around her waist, holding her close.
Before she could move his hand to a more platonic place, he was extending his stick, catapulting them onto the ground.
His baton went back to the normal size for a moment, but then it went long again, helping to lift them to a building.
For the next thirty seconds, Chat kept up the game of leaping from place to place, finally stopping on a street near her house.
"You need to get home." Hs panted, leaning against a nearby building.
"I will." Marinette nodded, holding out her hands. "But, first, you should take the akumatized object, so that Ladybug can purify it when she arrives."
"Thank you, Marinette." Chat Noir smiled weakly, sighing gently as he tucked it into his suit's left pocket. "H-how did you learn to use a yo-yo like that?"
"Oh, ummmm…" Marinette nervously twiddled her thumbs, blushing. "I've seen Ladybug on the news and…uh, I guess I've practiced before…?"
"Ah. Good for you." Chat Noir nodded, lowering himself to a sitting position. "Good for you…"
"Chat, take it easy for the next few days, alright?" Marinette begged, frowning at him.
"Ladybug'll fix me right up. I won't need to take it easy." Chat cheekily grinned. "Now, get going."
Marinette obeyed, scampering off. However, she ducked into an alley the moment Chat Noir couldn't see her anymore.
"I don't like the idea of Chat Noir laying in a street, with an akumatized object, no less." She hummed to Tikki, releasing the Kwami.
"Right, Marinette!" Tikki chimed, knowing what it was time for.
"Tikki, spots on!" Marinette ordered, summoning her familiar costume.
Then, holding her real yo-yo tightly, she flung herself towards her friend.