The lair was filled with shouting. Not an argument about battle strategy. Not a fight over the last slice of pizza.

No, this was just another Mari and Cat screaming match.

"You are so annoying!" Mari snapped, arms crossed.

"Oh yeah?" Cat shot back, hands on her hips. "At least I don't act like I'm better than everyone else!"

"Maybe that's because I actually am better than you."

Cat gasped, offended. "You are not! You're just a cold-hearted jerk!"

"And you're an embarrassment!" Mari spat.

"Enough!" Leo groaned, pinching the bridge of his nose. "Can you two go one night without fighting?"

Mikey sighed dramatically from the couch. "I'd rather fight an army of Krang than listen to this."

Donnie muttered, "Statistically speaking, we'd have a better chance of survival against the Krang."

Raph just smirked. "I say we let 'em brawl. Maybe they'll finally settle it."

Mari cracked her knuckles. "I am so down."

"Guys!" Cat gasped, holding a hand over her chest. "Violence is not the answer!"

Mikey raised an eyebrow. "Says the ninja?"

"Exactly!" Mari rolled her eyes. "She fights like she's in some kinda anime filler episode."

Cat glared.

Leo groaned. "Seriously, what are you even fighting about?"

Cat huffed. "Mari acts like I'm some useless little kid!"

"That's because you act like one!" Mari shot back.

Raph snorted. "She's got a point."

Cat glared at him. "Oh, like you're never reckless?"

"That's different," Raph said smugly. "I actually win my fights."

"Wow, Raph," Donnie muttered. "Way to defuse the situation."

Mikey leaned toward Donnie. "Five bucks says they end up wrestling on the floor."

Donnie sighed. "Not taking that bet. Too high of a probability."

Meanwhile, Cat gritted her teeth and stomped up to Mari.

"You know what? I'd like to see you handle being me!"

Mari scoffed. "Oh, please. I'd thrive if I were you. No responsibilities, no expectations, just running around like an airhead—"

"Airhead?!"

"—with no clue how to be serious."

Cat puffed up. "Oh yeah? I'd love to see you try and handle my life, Miss 'I Think I'm Better Than Everyone!'"

Mari rolled her eyes. "I'd do it better."

Leo rubbed his temples. "I swear, if you two don't—"

Before he could finish, April walked in.

April blinked at the scene in front of her—the usual chaos of the lair, but this time with Mari and Cat arguing in each other's faces like two cats hissing over the same patch of sunlight.

She sighed. "Okay, what now?"

"They're at it again," Donnie muttered, adjusting his goggles.

Mikey gestured lazily. "Mari thinks Cat's a reckless little kid, and Cat thinks Mari's a soulless robot."

April raised an eyebrow. "So... a normal night?"

"Pretty much," Raph confirmed.

Leo crossed his arms. "I don't even know why I bother trying to stop them at this point."

As if on cue, Cat snapped her head toward Mari. "You act like I never do anything right!"

Mari snorted. "Because you don't!"

April sighed again, but then she remembered something.

"Oh! That reminds me—look what I found today!"

She reached into her pocket and pulled out a small, glowing charm on a delicate chain. It shimmered in the dim light of the lair, a deep red with golden engravings swirling across its surface.

Immediately, Cat's eyes lit up. "Ooooh, shiny!"

April chuckled and handed it to her. "Figured you'd like it. It's from this weird old antique shop. The guy said it's got mystical properties or something."

Donnie perked up. "Wait, mystical? Like, actual magic? Or just some scam to sell overpriced jewelry?"

April shrugged. "Honestly? Probably a scam."

But Cat was too busy admiring the charm to care. "It's so pretty!" She turned it over in her hands, watching how the light reflected off the engravings.

Mari rolled her eyes. "Seriously? You're just gonna take some random old guy's word for it?"

Cat stuck her tongue out. "Oh, I'm sorry, Miss I-Have-No-Joy-In-My-Life. It's a cool necklace!"

Mari scoffed. "Yeah, okay, whatever."

"Bet you'd break it in two seconds if you had it."

Mari narrowed her eyes. "You really think I'm that careless?"

Cat crossed her arms. "I think you don't know how to have fun!"

Mari snatched the charm from her hands. "I know how to have fun—I just don't make a fool of myself doing it!"

"Give it back!" Cat whined, reaching for it.

"Make me!" Mari taunted, holding it out of reach.

"Oh, I will!"

Before their brothers could intervene, the two girls stormed off toward the back of the lair, still bickering.

"You are so full of yourself!" Cat huffed.

"And you are so ridiculous!" Mari shot back.

Cat jabbed a finger at Mari. "I bet you wouldn't last a day as me!"

Mari glared. "And you wouldn't last a minute as me!"

"Bet!"

As soon as the words left Cat's mouth, the charm in Mari's hand glowed brighter. The engravings flared up, pulsing with golden energy, and suddenly—

A blinding light flashed, engulfing both girls.

Their yells of surprise were cut off in an instant.

Then—silence.

The glow faded, leaving the training room eerily still.

Mari blinked. Something felt... off.

She turned her head—only to see herself standing across from her, wide-eyed and frozen in place.

She looked down at her own hands—except they weren't hers. They were Cat's.

Mari's breath hitched.

"What the hell?"

Cat's in Mari's body screamed.

Both turtles stared at each other, their breathing uneven, panic setting in.

Something was very, very wrong.

Mari—now in Cat's smaller but chubbier, twitchier frame—felt a deep sense of dread settle in her gut. Her limbs felt weirdly light, her movements too bouncy, and her stomach was way too high up. She lifted her hands in front of her face.

No. No, no, no.

Cat—now in Mari's taller, more rigid body—felt a strange heaviness all over, as if she was suddenly carrying extra weight she wasn't used to. She took a step forward and immediately felt off-balance in a way that wasn't just her usual clumsiness—her stride was too long.

They slowly locked eyes.

Mari's breath hitched. "...Why do I sound like you?"

Cat froze. Her throat felt different. She touched her face—not hers. A lump formed in her throat.

"W-Why do you sound like me?" Cat's voice cracked.

Silence.

Then—they screamed. Again.

"WHAT THE HELL?!" Mari shrieked, flailing her arms, except it looked ridiculous coming from Cat's body.

"WE SWAPPED BODIES!!" Cat wailed, gripping Mari's shoulders (her own shoulders?!?!) and shaking them wildly.

Marishoved her back. "DON'T TOUCH ME! I don't even wanna be IN your body!"

"YOU THINK I WANNA BE YOU?!?" Cat yelled back.

Mari whipped around, trying to process. This was impossible. This wasn't real. It was just a bad dream, right? She would wake up in her own body, be annoyed with Cat like usual, and—

She caught a glimpse of her reflection in a broken mirror propped against the alley wall.

It was Cat's face.

Her stomach dropped.

Cat saw it too and immediately freaked out. "AHH—OH MY GOD! I LOOK SO MEAN!" She grabbed Mari's (her own) face and squished her cheeks. "WHY AM I SCOWLING?! STOP SCOWLING!"

Mari slapped her hands away. "STOP TOUCHING ME, YOU'RE TOUCHING YOURSELF!"

Cat whimpered. "Mari, what do we do?!"

Mari clenched her fists—except they weren't her fists, they were Cat's smaller, shakier ones. "We fix this. We get that stupid, shiny thing and reverse it."

Cat frantically patted her (Mari's) pockets. "W-Where's the stone?! Do you have it?! It was shiny, maybe I took it—"

They both searched their respective belts, but the stone was gone.

Cat gasped. "Mari—what if it only worked once?! What if we're stuck like this forever?! What if I never get to be ME again?!"

Mari snapped. "Then we burn April's apartment down and pretend we were never born!"

Cat gasped. "WHAT?!"

"I'M PANICKING, OKAY?!" Mari threw her arms up. "YOU THINK I WANNA BE YOU FOREVER?! I CAN'T LIVE LIKE THIS!"

Cat looked equally horrified. "I CAN'T BE YOU EITHER! YOU'RE SO MEAN! I can already FEEL my anger issues getting worse!"

Mari groaned, dragging a hand down her (Cat's) face. "Alright. Okay. Breathe. Breathe."

Cat nodded rapidly, inhaling. "Breathe. Right. Breathing is good."

Silence.

Mari stared at her. "Why do you look like you're about to pass out?"

Cat, still panicked, wobbled. "Because I am!"

"Okay, STOP. You're in MY body. That means you're strong now. You don't pass out."

"But I have your metabolism now! What if I forget to eat and STARVE?!"

Mari groaned. "Oh my god, I'm gonna kill you."

"You'd be killing yourself!"

Mari paused. "...Shit."

Mari grabbed Cat by the shoulders—her own shoulders, ugh, this was so weird. "Okay, listen to me, we cannot tell our brothers."

Cat's eyes widened. "WHAT?! Why not?!"

Mari groaned. "Think about it. Leo will FREAK OUT. Raph will never let us live this down. Donnie will probably poke us with needles and run tests, and Mikey—oh my god—Mikey will turn this into the worst joke of all time."

Cat winced. "Oh no. You're right. Mikey's gonna call us 'Maricat' and 'Catari' or something stupid—"

"EXACTLY!" Mari hissed. "And what if Donnie CAN'T fix it? Then what?! Do you wanna be like this forever while they all laugh at us?!"

Cat shuddered. "No. No I do NOT."

"Good. Then we play it cool. We act normal until we figure out how to fix it ourselves."

Cat's face fell. "But... I don't know how to act like you! What if I mess up?"

Mari smirked. "Then you better learn fast, Mari."

Cat whimpered. "Ohhh, I have a bad feeling about this..."

Mari (in Cat's body) and Cat (in Mari's body) walked back into the lair, forcing themselves to act like nothing was wrong. If their brothers found out, they'd never hear the end of it.

But... they weren't expecting this.

The moment they stepped in, Leo, Raph, Donnie, and Mikey all looked relieved.

"Finally," Raph muttered, stretching out his arms. "Guess they got all that outta their system."

"About time," Leo agreed, rubbing his temple. "I was two seconds away from locking them in a closet until they worked it out."

"We should've done that years ago," Donnie added.

Mikey gasped dramatically. "Wait. Does this mean—you two aren't fighting anymore?!"

Mari (as Cat) forced a bright, fake smile. "Nope! All good!"

Cat (as Mari) crossed her arms, trying to mimic Mari's usual attitude. "Yeah. We're cool."

Mikey nearly choked on his own spit. "Has the world ended?! Is this a fever dream? DONNIE, CHECK MY TEMPERATURE!"

Donnie just shoved him away. "Shut up, Mikey. We should just be grateful."

Raph let out a satisfied sigh, flopping onto the couch. "Man, it's so much quieter already. It's kinda nice."

Leo nodded. "Yeah. Let's enjoy it while it lasts."

They didn't question it further.

And that was great news for Mari and Cat.

Or so they thought.

At first, Mari thought it was funny.

Her brothers were actually nicer to her (well, to Cat) than they were to her real self. No snide comments, no glares, no sarcastic remarks.

Then she started noticing things.

Like how little they respected Cat.

It started in training.

Leo paired her with Mikey.

"Uh, why am I not sparring with someone better?" Mari (as Cat) asked, tilting her head. "Like, I dunno, anyone else?"

Leo sighed. "Cat, we always pair you with Mikey."

"Why?"

Mikey grinned and threw an arm around her. "Because we're the dumbasses of the family, duh!"

Mari froze.

Wait. What?

"Hey!" She pulled away. "I—I mean, Cat isn't dumb!"

Silence.

Leo and Donnie exchanged a look.

Raph snorted. "Smart people don't talk in third person."

Okay. No.

Mari gritted her teeth. Whatever. They just underestimated her. That wasn't new.

But it didn't stop there.

During training, Leo kept correcting her.

"Cat, your stance is off," he said for the fifth time. "You keep dropping your left foot—"

"Okay, I know how to fight, dude," Mari snapped.

Everyone stared.

Leo blinked. "...Right. Just making sure you remember."

Mari clenched her fists. Fine. Whatever.

Then came Donnie.

She was standing in his way when he literally picked her up and moved her.

Like. A. Child.

"EXCUSE ME, WHAT THE HELL?!" Mari shrieked.

Donnie just shrugged. "What? You're small."

Mari's eye twitched.

It got worse.

At dinner, she went to grab a slice of pizza—but Raph just handed her one instead.

"Here, shorty, I got it," he muttered.

"I can grab my own damn pizza, Raph."

Raph snorted. "Relax. No need to get your feelings hurt."

Mari stared at him. Was this a joke?

Then, to make matters even worse, Mikey patted her head.

That was it.

Mari snapped.

"DO NOT TOUCH ME!" she yelled, shoving Mikey so hard he toppled over.

Silence.

Mikey blinked. "Whoa. Who peed in your cereal?"

Leo sighed. "Alright, what's with you today? You're usually way more easygoing."

Mari stiffened.

She wanted to scream. Is this how they always treated Cat? Like she was some helpless, weak little idiot?!

No wonder Cat tried so hard.

But she couldn't say anything. She just muttered, "I'm fine," and ate her damn pizza.

For the first time in her life, she felt small.

Meanwhile, Cat was experiencing a nightmare of her own.

Being Mari meant everyone expected her to act like Mari.

Which was bad.

Because Mari was terrifying.

Training started and Leo paired her with Raph.

Cat (as Mari) paled. "W-Wait, why am I fighting Raph?"

Raph arched a brow. "Uh, because you always fight me? Duh?"

Oh.

Oh no.

Cat gulped. "Oh. Right. Hehe..."

Then sparring started.

And Raph did not hold back.

He lunged. Hard.

Cat barely dodged before yelping, "WHAT THE HELL, RAPH?! TOO HARD!"

Raph froze. "What?"

Cat held up her hands (Mari's hands) in surrender. "L-Let's go easy, okay? No need to break bones!"

Now everyone was staring at her.

Leo and Donnie exchanged worried looks.

Mikey blinked. "Uh, Mari? Are you feeling okay? You're not usually... you know. A coward."

Cat stiffened.

Oh no. They were onto her.

Raph narrowed his eyes. "You sick or somethin'?"

Cat panicked.

"Nope! Just, uh, giving you a break!" She forced out a nervous chuckle, trying to act cool. "Didn't want to embarrass you in front of everyone!"

Raph scowled. "The hell does that mean?!"

"Uh—nothing!"

Leo narrowed his eyes. "Mari, you've been acting weird all day."

Cat swallowed hard.

"I'm fine," she muttered.

"Yeah, sure," Donnie said. "And Mikey's a genius."

"Hey!" Mikey pouted.

Cat forced herself to keep her head down. If she acted weird, they'd figure it out.

She just had to survive until she and Mari could fix this.

Even if it meant pretending to be someone she clearly wasn't.

Mari (in Cat's body) clutched Cat's Tessen, flipping it open and shut anxiously. It was so light, so delicate compared to her own tanto—a weapon built for precise, brutal strikes. She felt like she was holding a toy.

Meanwhile, Cat (in Mari's body) was gripping Mari's tanto in her shaky hands, trying not to let it show. The blade felt sharp, dangerous, and too real. She had seen Mari use it with terrifying efficiency, but now she had no idea how to wield it properly.

They had no choice but to act like everything was fine.

Leo led the group across the rooftops, scanning the streets below. "Standard patrol. If you see anything, call it. Don't engage unless necessary."

Raph scoffed. "Yeah, tell that to the brats."

Cat (as Mari) instinctively flinched, expecting to be lumped in with Mikey—but Raph was looking right at her like she was actually responsible. She blinked. Right. Mari doesn't get treated like an idiot.

"Mari knows better," Leo said firmly, nodding in her direction. "It's Cat we have to worry about."

Mari (as Cat) clenched her jaw, biting back her usual snark. Normally, she wouldn't care what they thought, but hearing it firsthand was different. She had always known her brothers didn't take Cat seriously—but experiencing it? It sucked.

Mikey nudged her playfully. "You gonna start actually listening tonight, KitKat?"

Mari rolled her eyes, forcing herself to act in character. "Pfft, no."

Raph groaned. "Unbelievable. Try not to get in the way."

That was it. No faith. No trust. Like she was some dumb little kid tagging along.

Before Mari could process how much that pissed her off, Leo suddenly signaled them to stop. The group crouched down as a bunch of thugs loaded stolen equipment into a truck below.

"Okay," Leo whispered. "We go in fast and quiet. Mari, you take point."

Cat (as Mari) stiffened. "W-what?"

Leo frowned. "You're the fastest. You can take out the first guy before they know we're here."

They wanted her to go in first. No hesitation. No doubt. They expected Mari to be competent. Strong. Not a liability.

This was how Mari was treated.

Swallowing, Cat nodded and dropped down silently, gripping the tanto in both hands. She tried to move how Mari did—efficient, precise, deadly.

She crept up behind the first thug and hesitated. How did Mari do this so easily?!

Before she could overthink it, she smacked the guy upside the head with the handle of the tanto instead of stabbing. He grunted but didn't go down.

Oh no.

The thug turned. Cat panicked and kicked him in the chest—way too hard. He went flying into a pile of crates with a loud CRASH.

Above her, her brothers froze.

"What the hell was that?" Leo whispered harshly.

"Yeah, Mari," Donnie said. "You don't fight like that."

Cat's stomach twisted. She had messed up. She wasn't moving like Mari.

Before she could fix it, Mari (as Cat) was suddenly at her side, gripping the Tessen.

"Oh, for the love of—" Mari huffed before swinging the Tessen straight into another thug's face. It was meant to knock him out, but it barely fazed him. The guy just stumbled back, dazed.

Mari stared at the Tessen like it had personally betrayed her.

Right. Cat's weapon wasn't built for full-force attacks.

Before she could correct it, Raph yanked her back.

"What the hell are you doing, Cat?!" he snapped. "You didn't even hit him right!"

Mari clenched her fists. "I—"

"You're lucky you're even out here!" Raph continued. "You can't just throw yourself into fights like a dumbass!"

Dumbass. Liability. Screw-up.

Mari's heart pounded. She always knew they treated Cat like a joke, but feeling it? Living it? It was different.

Meanwhile, Cat (as Mari) was getting the opposite treatment.

"That was sloppy," Leo said, looking at her in concern. "You hesitated. You never hesitate."

"Yeah," Donnie added. "That was a total Cat move."

Cat gulped. They expected Mari to be perfect. They trusted her to be strong. She couldn't mess up without them noticing. She wasn't used to that.

Mari (as Cat) scowled. She was so over this.

"Can we just finish the damn fight?" she snapped.

The guys blinked at her.

Right. Cat didn't talk like that.

"Jeez, someone's cranky," Mikey muttered.

They all turned back to the fight, but Mari and Cat exchanged looks.

They had swapped bodies and now they were getting a front-row seat to how differently they were treated.

And they both hated it.

The fight wrapped up quickly, but Mari (as Cat) and Cat (as Mari) weren't really paying attention anymore. Their minds were racing.

Cat—trapped in Mari's body, forced to be perfect, to never mess up, to never hesitate—was overwhelmed. She felt like she couldn't breathe. This is what Mari deals with all the time? The constant weight of expectation? The pressure to be the best, no room for failure?

And Mari—trapped in Cat's body, being doubted at every turn, treated like she was incapable, weak, a screw-up—felt humiliated. Every time she tried to prove herself, Raph or Leo would shut her down. This is what Cat puts up with every day? Never being taken seriously?

When the fight ended and the thugs were dealt with, Leo called it. "Alright, let's head back to the lair."

Mari and Cat stayed quiet the entire way home.

Mikey tried to joke around, but even he noticed something was off. "You two aren't arguing? That's gotta be a first."

Raph snorted. "Let's not question it."

But Mari and Cat weren't talking because they were both thinking.

As soon as they were in their shared room, Mari slammed the door shut.

"We need to fix this," she said immediately.

Cat—still stuck in Mari's body—was pacing back and forth. "Yeah? And how?! We don't even know how this happened!"

Mari crossed her arms, still uncomfortable in Cat's shorter frame. "I think we do."

Cat stopped. "...We were fighting. Like, bad."

Mari sighed. "Yeah. And now I get why."

Cat swallowed, not used to seeing herself—Mari in her body—look so... regretful.

"You think I don't try," Mari said, voice quieter than usual. "You think I don't care about how I make people feel. And I thought you just liked playing the victim. That you liked attention."

Cat bit her lip. "And I thought... you didn't know what it was like to be treated like garbage. I thought you had it easy." She let out a dry laugh. "But I was so wrong."

They looked at each other.

"You don't have it easy," Cat admitted. "You have to be flawless all the time, and if you mess up, it actually matters. Like—Leo notices. Raph gets mad. They expect you to be strong." She hesitated. "I don't think I could handle that."

Mari clenched her fists. "And you don't have it easy either. You try, but they don't let you. They act like you're not good enough before you even get the chance. Like you're doomed to fail. I get it now. No wonder you act out—it's the only way they even acknowledge you."

The room was silent for a moment.

Mari sighed and rubbed the back of her neck. "...I'm sorry."

Cat blinked. "What?"

"I mean it," Mari said. "I didn't get it before, but I do now. I was an ass."

Cat swallowed. "...Me too. I thought you were just being mean, but I didn't realize you were under that much pressure. I'm sorry too."

They locked eyes, both meaning it.

And suddenly—a rush of energy surged through them.

A bright light flashed between them, and they felt a pull—like they were being yanked back into place.

When the light faded, Mari blinked. She looked down at herself—her actual hands, her war fans strapped to her side.

Cat gasped and touched her own face. "Oh my god, I'm me again!"

Mari let out a relieved breath. "That was awful."

Cat nodded way too fast. "Never again. Never ever again."

They stood there for a second.

Then Cat cracked a grin. "You know... I kinda rocked your body, though. Maybe I should be the scary one from now on."

Mari rolled her eyes. "Please. You were so stiff, Leo was about to start asking if I was sick."

Cat snorted. "And you? You sucked at being me. You were way too quiet."

"Because I had to listen to Raph and Leo treat me like a literal child!"

Cat winced. "...Yeah. That part sucked."

Mari smirked. "See? I handled being you way better."

Cat pouted. "Nuh-uh!"

Mari crossed her arms. "I literally won a fight with your weapon. You barely knocked a guy out."

"Okay, that's because—!"

Their arguing picked up again, loud and dramatic, but this time?

It wasn't mean.

They weren't really mad.

And despite how terrible the swap had been, they understood each other now.