A / N :

Welcome to Under Oath!

This is my first fanfiction and I am super excited to share it with you. I hope to publish a new chapter every Friday (started Jan 20, 2022). For aesthetics and live updates into my writing process, you can follow me on social media (links in my bio) . If you are on AO3 and prefer that reading format, this fic is also being updated under eoscenes, same story title and username on that platform.

Okay. Let's start the ride!

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"YOU. . . MUST HAVE BEEN PRETTY surprised to discover there was another holder."

The voice came from behind, soft, tentative. He'd known she was coming, of course, with his feline hearing. But Chat Noir didn't turn his head.

He set his jaw, staring into the brilliant golden afternoon. The Eiffel Tower rose to prominence in the distance, the late afternoon sun creeping closer to the horizon. Tonight's sunset would be brilliant and rich—common for autumn in Paris—but he felt none of the warmth.

Don't look at her.

"I'm really sorry, Chat Noir." Ladybug sat down next to him, swinging her legs over the ledge of their spot, their rendezvous point for patrols and meetings.

The meetings and patrols didn't matter much to him. Not as much as the other things. The privacy. The late nights. The aimless conversations and laughter. Their spot. To him, this was his favourite place in the world.

Chat Noir had a new partner to defeat an akuma today. Scarabella. Ugh. Scarabella was out of her element and sassily aware of it, which just made him more antagonistic in turn. Really, his prickly attitude in today's battle had nothing to do with the replacement. It had everything to do with whom she was replacing.

He'd laid eyes on Scarabella for the first time and panicked, thinking his greatest fear had come to life. Scarabella had said his Ladybug was out of town, but what if that was just to keep his morale up? What if his Lady was sick? Dying? Dead? Never to patrol or battle enemies with him again, forever replaced by some witty smartass with voluminous hair?

Chat Noir had been sitting at their spot for nearly an hour, squinting at the skyline until he could believably say the liquid in his eyes was from glare instead of fear, trying not to imagine a world where he and his Lady never met again.

Ladybug cast a gentle look in his direction—he could see it, those sapphire eyes, even in his periphery. "I should have told you. I mean, if I had found out that you told someone your secret identity, I'd. . . probably be upset, too. I'm really sorry I hurt your feelings."

Chat Noir blinked, willing his eyes to dry. He was seventeen now—very nearly eighteen—and in the four years that Ladybug and he had been partners, she'd never shared her true identity, and she'd forced him to do the same. It was too dangerous, as the guardians of Paris—hers with a capital G, and his with lowercase.

If that knowledge fell into the wrong hands, it would be a swift game over. Miraculous wielders were forbidden to know each other's daytime personas. If Hawk Moth corrupted one of them, the secrets about the rest would spill out as easily as water from a faucet.

So in telling Scarabella, Ladybug had hurt him, deeply. Did he not deserve a warning at least? Still, his heart refused to let her bear an ounce of that weight. His sole purpose was to protect his Lady, even from her own guilt.

Chat Noir wondered if his anguished thoughts would tint his words insincere when he said: "You didn't hurt my feelings. You did everything right."

Ladybug hadn't done everything right.

She could have told him a replacement would be coming. She could have told him that there was someone in her life that she had confided in, when he'd been in self-imposed isolation for four years, trying to live up to her moral standards. Below the skyline, civilians basked in the early evening, toddlers laughed, even the pigeons seemed to amble instead of viciously scurrying for food.

"Paris will always need a Ladybug superhero to watch over her. It's just, I realised that if one day that hero wasn't you, my Lady, since we don't know each other's identities, that means. . . I'd never see you again," he confessed hoarsely. "Ever." Chat Noir placed both his palms on the concrete ledge, turning his head away. "You know, I just don't know if I can bear it."

A gentle pressure landed on his right hand. Chat Noir met her caring, earnest eyes and felt his frantic heartbeat settle down.

When they first met and Ladybug was still a mysterious, irresistible stranger, his heartbeat skipped whenever he saw her. Thinking of her brought around giddiness and fantasies and butterflies in his chest.

Now, terrifyingly, Chat Noir had familiarity instead of giddiness, memories instead of fantasies, and the butterflies had become this crushing weight on his chest that only abated when he could touch her.

There were moments like this that gave him such an epic sense of calm and completion that he thought, I really love you. But he'd thought that yesterday. And the day before. Each new sunrise, he was convinced this was the deepest in love, the most hers he could ever be, and by each sunset he had proven himself an idiot because she would never feel the same.

"I'll never abandon you, kitty cat," Ladybug murmured, squeezing his hand in hers.

The sunset sky seemed to curl around them. Chat Noir was close enough to trace the different whorls of blue in Ladybug's eyes—sapphire, with flecks of sky and periwinkle. The sunset sky seemed to curl around them.

She was heartbreakingly beautiful. He knew that in his soul, even though the quantum masking in their suits obscured any true facial features. If all the people who had ever seen Ladybug described her to a forensic artist, no two drawings would agree.

But Ladybug was just as beautiful as a person, and Chat Noir saw it every time they were together. Her morality, her quick wit, her stubbornness. Those qualities shone out of her and hit him squarely in the chest.

And it was starting to bruise.

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Ladybug anchored her magical yo-yo around the TV antenna on top of the Dupain-Cheng's bakery.

Aside from those training-wheel weeks back when she was thirteen, the yo-yo always felt like an extension of her body. She hardly had to think to navigate around Paris with neck-breaking speed. She'd been curious about it back then, but no amount of research could make the physics make sense to her.

The string contracted, dragging her soaring body through the air. A warm breeze caressed the exposed lower half of her face. Her momentum carried her into a perfect somersault and onto the balcony.

Ladybug slipped into her bedroom through the sunroof and transformed. Marinette's kwami, a mouse-sized magical creature with hot pink fur and enormous sapphire eyes, materialised from her ruby earrings.

The first thing Tikki did was sigh.

"It's a good thing you spoke to Chat Noir after sending Scarabella," Tikki said, folding her paws in front of herself. "He really loves you, Marinette."

Gah. Whenever Tikki pulled her baby eyes, Marinette was utterly helpless.

It was incredibly deceiving; the way kwamis manifested in the mortal realm. With giant eyes, tiny, rounded limbs and a plump body, no-one would ever guess that they were overpowered entities as old as the universe. Kwamis levitated, phased through solid matter, travelled to interdimensional realms, and bestowed their unique abilities on human wielders through their Miraculous—a jewel conduit for sacred magical power.

And one of Tikki's many powers was the power of the gentle guilt trip.

"He really loves the woman in the suit," she defended. "Not Marinette. There's a difference. A pretty huge one."

"Maybe so. But he's wanted to know your identity for so long. It must have been a shock to discover that you trusted Scarabella and not him."

"A surprise, yes." As Marinette slipped her ballet flats off in favour of her inside slippers, her gaze landed on the posters decorating her baby pink walls. "But Chat Noir knows that we're just partners. And why it's too dangerous to tell each other. I have friends and confidants in my real life, too, and Chat Noir pales in comparison to some of those people."

It was impossible to stop the dreamy lilt from sneaking into her voice when she said those people.

Adrien, a name which must always be sighed instead of said. He modelled, fenced, danced, played the piano, spoke several languages, and above all, he was kind. So kind. And pretty. Giddy adoration washed over her at the mere thought of him.

Marinette couldn't help it. She'd printed the highest-quality posters of Adrien Agreste for this exact reason. Perfectly symmetrical features and lush blonde hair. He was a walking painting of summertime, all ripe plantlife and fields of sunflowers. It was almost like those were his real grass-green eyes staring back at her.

Adrien's eighteenth birthday was next week. She'd been working on his gift for a month, and had set all her search engines to notify her when an article mentioned the love of her life. He was the son of Gabriel Agreste, Paris' most exclusive designer, and a powerhouse idol in his own right. Therefore, Adrien's birthday party would be studded with more stars than Chloé Bourgeois' rhinestone handbag.

Marinette had to get his attention. She had to. She'd prepared her outfit, his birthday gift, the transportation to the Agreste mansion with her classmates, and seven different conversation starters depending on the potential times and locations of her inevitable run-in with Adrien.

If they were near a waiter, she'd ask about the canapes. If it was early into the event, she'd glance around at the people not-dancing and say "we should really get this party started" and ask Adrien to dance like he had in New York. And if it was late—

"Hm." Tikki observed Marinette's dreaminess with an odd stillness.

Marinette chuckled bashfully. "What?"

"Marinette!" Her mother's voice drifted upstairs, through her bedroom door. "Dinner's ready!"

Marinette tucked all thoughts of Scarabella and the mistakes she'd made, and Chat Noir and how ridiculously green his eyes were when he was sad—and even Adrien Agreste—away when the thought of food hit her.

"Coming, Mom!"

It had been such a long day. She was famished.

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There were bubbles floating in the air when Adrien walked into Francois Dupont High School.

For a second, the iridescence took his train of thought down a detour—watching the rainbows swirl on the round surfaces, wondering who blew them, wanting to pop one with his forefinger. But then Adrien cleared the entrance foyer.

Leaning against the wall, in the shadowy corner, was Nino Lahiffe, Adrien's bestest friend in the world. "Hey, Nino. I got to tell you something."

"No," Nino interrupted. He lowered the bubble stick from his lips. "I got to tell you something."

Nino took Adrien to a part of the school he never knew existed.

It was two stories down from ground level, accessible by a heavy door with lots of warning signs on it, mostly pertaining to the electrical hazards in the plant room beyond. It was lit by one bulb that was definitely on its way to dying, blinking frequently and casting the empty maintenance room in a weak blue light.

Adrien glanced around wherever he could, watching his feet for things that might trip him up. But Nino seemed to know his way around, walking straight to a desk in the corner.

Nino spun a wooden chair around facing the desk, hands clasping the back of it. "Sit down."

Adrien watched with a little amusement and a lot of concern as Nino rounded the desk, sank into the larger and cushier chair behind it, and crossed his feet on top of the wood.

Adrien sat.

Nino said nothing, puffing bubbles into the air like cigarette smoke.

Adrien folded his hands underneath his thighs.

"Uh. . ." he murmured, unsure what to say.

Nino had been having a rough time this week. Relationship troubles. That was exactly what Adrien had wanted to address when he walked into school.

Was there music playing?

There was music playing.

Some dusky, sultry jazz was pouring out from a handheld radio on the right-hand side of the desk. A stack of books sat on the left-hand side. Behind the desk was a sprawling poster of the New York skyline. With the crime film soundtrack and bad lighting, Adrien expected to see a private investigator from the underbelly.

Not Nino, in the damp basement of their high school.

"When did you set all this up?" he asked casually.

Nino slammed a fist onto the desk. Adrien flinched; that had to have hurt.

"I'm the one asking questions. Remember what I told you yesterday?"

Yeah. Adrien did. Nino had gotten it into his head that Alya Césaire—his girlfriend since seconde—was in love with Chat Noir, and soon to dump him. It was ludicrous and impossible and just plain dumb, and yet it was something Adrien could have easily fixed for his best friend.

So he'd gone to Alya's place last night as Chat Noir, intent on setting things straight. With brilliant success, in his opinion.

"I got proof now." Nino held up his cell phone, the glaring brightness doing more for the room's lighting than that struggling bulb overhead. "What do you say to this?"

Nino shoved the screen into Adrien's face. It showed a video, paused on a specific frame of Chat Noir and Alya hugging.

For fuck's sake.

That was taken out of context. They'd hugged only after she'd laughed—more like guffawed—in his face for ever thinking she could love anyone but Nino. She was deeply committed to her boyfriend.

"Uh," Adrien stamped down the urge to swear at the twist of fate. He reached for the radio dial and turned the smooth jazz down. "Come on. That doesn't make any sense. You're wrong. That's not at all what happened."

Nino stood and dialled the music back up, eyes piercing and inquisitive. "How do you know? You were there? You're in on it, too?"

His best friend was just projecting. On most days, Nino was incredibly mellow. He was slow to anger, easy-going and forgiving. But, damn, Adrien knew there was a dramatic side to him. And now he had to parry with it, taking extremely careful steps not to set him off.

"No, no, of course not." Adrien shook his hands. "But it's impossible. I'm sure this is just a misunderstanding. Alya and Chat Noir have nothing in common."

Adrien tried to think of all the times he'd interacted with Alya as his superhero persona, and he was damn sure there were about—what?—four? Five?

He didn't count those times when she pleaded with them for an interview with the Ladyblog, Alya's online website dedicated to the heroes of Paris. She always glossed over his presence in favour of his Lady. I mean, if Alya had to have a celebrity crush, the entire world and then some knew it was Ladybug, not him.

"They barely know each other." Adrien turned down the crooning saxophone sounds, intent on making Nino listen. "Alya is just a superhero fan. She's been filming Ladybug and Chat Noir, that's all."

Nino frowned, leaning closer to Adrien, hands propped up on the desk. "They know each other well enough."

"But no-one knows Ladybug and Chat Noir's secret identities," he reasoned. "Can you imagine Alya falling in love with someone she doesn't really know? The girl who wants to be a reporter? Who always wants to know the truth no matter what? Who wants to share everything with the boy she loves?"

Yeah. Think, dude. Adrien could see he was getting through to Nino. In the watery lighting, he saw a flash of uncertainty cross his best friend's face. And when the angsty wall came down, he knew Nino didn't truly doubt Alya. He doubted himself.

But then Nino turned the stupid fucking jazz back on.

"They actually know each other much better than you think!" he exclaimed.

Adrien painted a comforting smile on his face. "You can't assume that from this video."

"Listen." Nino dropped his head with a heavy sigh and walked around the desk. "Here's what you don't know. I'm not talking about the video, dude," he said cryptically.

Nino kneeled to the ground at the side of Adrien's chair. His hands landed, faster than a blink and weirdly heavy, on his shoulders, eyes blazing with determination. "I'm talking about something I shouldn't be telling you. A mind-blowing secret."

Uh-huh.

"Alya is a superhero."

Huh.

"She's Rena Rouge."

Adrien's brain went numb. "Wha—"

"Shh," Nino hissed, placing his forefinger to Adrien's lips. "I know what you're about to say. That's nonsense." He got to his feet, gesturing wildly with his hands. "And how would Nino know that anyway?"

Yeah. What the hell was going on?

Nino turned his back to Adrien, wrangling with himself for one last faltering second.

"I know because I'm a superhero, too."

Adrien stopped breathing. His best friend turned around, walking closer, and Adrien wished he could pause time so his mind could catch up with his surroundings. God, would the jazz just shut up?

"I'm Carapace."

Adrien had walked into school with a fair idea of how the morning would go.

He would tell Nino the new information he'd obtained—Alya 100% doesn't love Chat Noir—and then the lovebirds would make up, and then everything would be well again. He and Marinette would then make gentle fun of Nino's melodrama at their usual cafeteria table at lunchtime. Gentle because Nino would undoubtedly still be a bit sensitive, and because Adrien couldn't envision Marinette ever saying anything truly mean.

That's how it was supposed to go.

That's— how. . . it. . .

"You're. . . Carapace? But—"

Adrien pictured the Carapace he knew. He'd called him the Lean Green Machine in his head. Tall, tanned, with quick jokes and unwavering determination. As one of the earlier wielders to be given a Miraculous, Carapace was great for easing new, uncertain heroes into the team.

Then he pictured Rena Rouge. Clad in orange that brought out her amber eyes and auburn hair, Rena Rouge was slick-talking and full of creative ideas. She was trained in melee combat, but best used as a mastermind. No-one could out-think her illusions.

How could they have been superheroes and hidden it so well from each other? Adrien had once tried to date, with disastrous consequences, while juggling his duties as Chat Noir. Kagami Tsurugi was his first girlfriend—if someone he'd always held at arm's length physically and emotionally was considered a girlfriend—and his last.

How did they do it?

Nino. And Alya.

Nino and Alya.

Oh.

Adrien leapt to his feet, the chair crashing to the ground behind him. Whatever. Consider it percussion to accompany that smooth jazz.

"The two of you know?" he accused, voice emerging harsh and way too accusatory. Adrien remembered that he was supposed to be a guileless schoolboy, and softened his tone. "You know each other's secret identities?"

"Of course. Alya and I have never kept anything from each other," Nino said, full of pride. Then his features darkened. "Until now. All that Chat Noir business."

"Wait a sec. I don't understand. I thought that secret identities had to be protected at all costs. If it were true, you'd never just tell me like that," Adrien insisted, watching Nino with wary eyes. "Ladybug would never agree to that!"

I'll never abandon you, kitty cat.

Nino frowned at Adrien, hands on his hips. Nothing in his posture was guilty or defensive. "Are you kidding? Ladybug is the one who gave us both our Miraculous at the same time."

She wouldn't. She said. . .

The truth pierced Adrien like a bullet. In through his heart and out along his spine. Surely, that deflating feeling in his chest was his body collapsing on itself.

"No. That's impossible."

Ladybug hadn't let him reveal himself in all the years they'd been working together. Claimed it was too dangerous. Claimed it was to protect them both. No Miraculous wielders should know about each other until Hawk Moth was defeated. But Nino. And Alya. Nino and Alya.

"What are you trying to say? That I'm lying or something?"

"No, no. What I meant was. . ." Adrien squeezed his eyes shut and dragged all his wayward thoughts back onto track. He could still save this morning.

"Okay. You're Carapace, she's Rena Rouge, and Ladybug's okay with this," he rattled off, voice trembling. "But, it still isn't like Alya or Chat Noir to be. . ." he waved his hand suggestively ". . .you know."

"You don't know what Chat Noir really is!" Nino yelled. "But I do. I'm part of the team. I see how he acts in real life. Sure, as soon as Ladybug shows up, he throws himself at her feet with roses and big declarations."

With hands clasped romantically, Nino leaned up to Adrien's face and mimicked kissing his cheeks. Then his lips flattened into a stern line. "But he gets blown off every time! Because Ladybug thinks he's obnoxious, and she's right!"

Oh, God. Adrien thought Carapace liked Chat Noir.

Lean Green Machine. They were the first two boys on the team, and their dynamic was like a well-oiled engine in his opinion. When he made those cheesy jokes, he was certain that Carapace would see the pompous irony for what it was. A cheap pun or an innuendo wherever it would fit—ha, wherever it would fit—because he was going for humour so bad that it was good.

But Carapace didn't get it. And neither did Ladybug.

"And then, whenever Rena Rouge shows up, it's like: well, hello there, pretty lady." Nino caressed Adrien's chin, the mocking touch an uncomfortable reminder of just how many ways this situation was truly fucked up. "You look so fine. You smell so good."

Fucked. Up.

"So yeah! It's easy to figure out that the first mission I missed— I mean, Carapace missed, he made his move," he said furiously. "And bam, this is what happened."

Adrien watched with a hurricane of thoughts in his head—Carapace, Rena Rouge, Nino and Alya, Ladybug lied to me—as the anger trickled out of his best friend. Nino hung his head, sniffing quietly.

"Now, I'm all alone. I've lost the love of my life." He held his phone to his eyes like it was a lifeline, a window into the world he wanted, where Alya would never leave him. Nino's lip trembled with rage, and he muttered violently, "If I could, I'd sew his sweet-talking mouth shut with his own whiskers."

Adrien attempted a conciliatory smile in case Nino glanced at him for support, but he was sure it looked pained. Or panicked. Or constipated.

Because, well, how could he even begin to fix this?

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A / N :

Whew. Long chapter, apologies.

Note: The akuma class has been aged up and I interpreted each season of MLB to take roughly a year. Marinette is 17, Adrien is going to turn 18 in the next chapter. This fic departs from canon after the events of Scarabella/Rocketeer as you saw, but I will stay very close to the lore and characterisation given to us (with angsty character development lol). If there are any other departures from canon, I will mention them in the notes. Readers feel free to point them out, too!

I'd love to hear your thoughts!

Aimee <3