"GET BACK HERE, YOU THIEVING WRETCH!"

Sly Cooper, legendary master thief, was running very fast.

This was because he had the King of Monsters' crown nestled in his arm, and the captain of said king's Royal Guard objected to that.

Her objection was very strong, very quick, very loud, and very murdery.

It was a real test of his agility and endurance – nice to have a challenge, he mused, although he'd prefer something a little less deadly – but he had so far evaded the constant barrage of magical spears. He was keeping ahead of her, just about.

But he quickly discovered that she did not give up.

Sly was running over a high bridge in the dark, cavernous stretch of the Underground known as Waterfall. He glanced over his shoulder to check the captain's progress – and ran straight into his constant pursuer and much less constant paramour, Carmelita Fox.

She reacted quickly, shoving her shock pistol in his face. "Hold it right there, Ringtail! If you thought you could avoid me by creeping around underground, you have another thing coming!"

"Carmelita!" he said, raising his hands. "Am I glad to see you! I could really use your help."

Carmelita's eyes darted to the crown before she fixed her glare back to Sly's face. "Let me guess. You did something stupid, and now you've irritated someone you can't handle by yourself."

A battle-cry tore through the air, reverberating off the stony walls. It was getting closer.

"NGAAAAAAAAAHHHHHHH!"

"...Something like that," admitted Sly.

Carmelita sighed, her shoulders sagging. "...I'll handle this. Get behind me."

He grinned. "Gladly!"

"And keep your mouth shut!"

His grin diminished, but only slightly. "Sure."

Carmelita looked across the bridge as the sound of footsteps grew louder.

The captain appeared.

She stomped toward them slowly. Her impressive framed loomed in the dim light. The clanking of her armoured boots echoed in the cavern, each step a metallic omen of doom. A furious pinprick of yellow shone from the depths of her helmet, boring into Carmelita.

The intimidation factor was only slightly ruined by the lanky skeleton in a red scarf nervously peering over her shoulder.

Carmelita stood her ground as they drew close – eyes hard, stance firm, shock pistol ready but at her side. Sly stood behind her and grinned sheepishly.

The captain stopped a few feet away from them. The skeleton managed not to bump into her.

She looked from Carmelita to Sly and back again. "... Who are you?"

Carmelita flashed her badge. "Inspector Carmelita Fox, Interpol. And you are?"

The captain didn't answer immediately. Then she whipped off her helmet – revealing scales, an eyepatch, a vicious grin – and shoved it into the arms of the skeleton, who clumsily grabbed it.

She stood tall. "My name is Undyne! Captain of the Royal Guard, right hand of King Asgore, hero of the Underground..." She raised a fist. "... and the person who's going to tear that crown out of your cold, dead hands if she has to!"

The skeleton struck a dramatic pose. "AND I, THE GREAT PAPYRUS," he declared, "AM ALSO HERE!"

"Royal Guard, huh?" Carmelita turned to Sly, glaring. "So it's exactly as bad as it looks. You stole the crown of an actual, sovereign king."

Sly raised a hand. "Carmelita, hear me out! That guy's been up to some real shady busine–"

He was cut off by a blue spear slamming into the wood next to him – a warning shot. Undyne's eye was twitching. "Shut your mouth, miscreant! Asgore is a SWEET, GOOFY LOSER and I will NOT allow you to tarnish his name!"

"OR STEAL HIS THINGS!" added Papyrus.

"Or STEAL his THINGS!" confirmed Undyne.

Carmelita took a deep breath. "Look," she said. "This raccoon is an unrepentant thief of the highest order –"

"Awh, thanks!" said Sly.

"And with that in mind," she continued, shooting him a glare, "I'm going to take him into custody and turn him over to the nearest Interpol-sanctioned prison. I would be happy to add this incident to his criminal record, following an official report from your local law enforcement agency."

Undyne watched Carmelita for a moment, her expression blank.

Then, she smirked.

Then, she grinned darkly.

Then, she let out a low, hoarse chuckle.

"Fuhuhuhu..."

Carmelita's eyes narrowed. "I fail to see the humour here."

"There's one little problem with that." Undyne jabbed a thumb at her own chest. "I am local law enforcement. And I don't do prisons. Not for a crime this serious."

Carmelita's grip on her pistol tightened. "Are you threatening this man?!"

"Oh, I don't know," said Undyne. "Are you protecting him?!"

"Ladies, ladies," said Sly. "There's plenty of me to go around."

"Shut up, dammit!" they both snapped, slightly out of sync.

Carmelita raised her shock pistol. "Back away slowly. I won't warn you again."

Undyne laughed. "You seriously think you can take me on?! I'm in a full suit of armour, and you look like you're dressed to go clubbing. There's no defensive merit to your clothing whatsoever."

"WELL, I THINK HER ENSEMBLE IS QUITE STYLISH," said Papyrus meekly.

"I NEVER SAID IT WASN'T!" screamed Undyne. "THERE'S FANTASTIC USE OF CONTRASTING COLOURS!"

Carmelita blinked. "Thank you...?" She shook her head – and smirked. "I admit you're probably better protected than I am. But there's one thing you're forgetting."

"Oh?" said Undyne, her eye gleaming. "And what might that be?"

Carmelita shot her in the face.

Undyne hissed as the blast of electricity struck her. She doubled up, clutching her face. "You forgot," said Carmelita, "that you took your helmet off like an idiot."

Papyrus gasped. "UNDYNE! ARE YOU OKAY?!" He offered her helmet to her – but she didn't move. She stood still, face covered. "...UNDYNE? WON'T YOU NEED THIS...?"

Undyne did nothing.

Then she burst upwards.

"No! I won't!" She was grinning. "Because she's not going hit me again!"

Carmelita glared. "We'll see about that."

With a low 'vwom', a spear materialized behind Undyne's shoulder – then another, and two more, and a further five, and dozen duplicates. They hovered in the air as Undyne created a final one in her hand. "If it's a fight you want... it's a beating you're going to get!"

She threw the spear – and the rest followed.

Carmelita and Sly dodged backwards, rolling and jumping and twisting mid-air. They managed to avoid being skewered, slipping through the tiny gaps that emerged.

The hail of spears ended suddenly. They lingered for a moment, stabbing through the thin wood of the bridge, before quietly fading from existence. Carmelita levelled her pistol at Undyne. "Is that all?"

Undyne didn't answer. Instead – her grin never wavering – she raised one foot and slammed it back down.

The bridge broke.

All four plummeted through the air. Sly landed gracefully and silently on a spiky rock, balancing himself on it without even looking.

Beside him, Papyrus smacked into the stony ground face-first.

He looked up, exasperated but uninjured. "I REALLY WISH SHE'D WARN ME WHEN SHE'S ABOUT TO DO SOMETHING COLLATERAL DAMAGE-Y."

They were both on a slight cliff. Below them, by the river, was a flat stretch of ground – which was where Carmelita and Undyne had fallen.

Carmelita had immediately angled herself towards the cliff wall, digging her boots into the rock in an attempt to slow herself. She tucked into a roll as she came to ground, managing to convert most of her momentum into horizontal motion to minimize damage from the fall.

Undyne, by contrast, opted for the Superhero Landing.

Her fist and knee slammed into the ground, causing cracks in the rock. She took her time getting to her feet, watching Carmelita with a smirk. "Well? I'm waiting!"

Carmelita leapt to her feet and fired repeatedly. Undyne summoned a spear and spun it, using it to block each shot. Then she threw it.

Carmelita ran to the side, keeping ahead of the spears that followed. She never stopped firing, but Undyne either blocked her shots with a spear, or simply leaned to one side.

"GO, UNDYNE!" hollered Papyrus from above. "SHOW THAT VEXING VULPINE WHAT FOR!"

"You got this, Carmelita! Take her down!" called Sly.

Papyrus started. "WHAT?! YOU'RE STILL HERE? I THOUGHT YOU WOULD HAVE ABSCONDED BY NOW!"

"And miss this?" smirked Sly. "Not a chance."

Undyne's spears were unrelenting, but Carmelita was a nimble target, sprinting and ducking. Undyne threw a spear into her path but Carmelita stopped in time, her boot kicking up debris as she twisted her heel against the ground. She immediately ran in the other direction and resumed shooting. Undyne growled to herself and summoned a new spear, back on the defensive.

After a few moments, Carmelita ceased firing. Undyne's defence was too solid – she'd never be able to hit her head on.

Sensing her opponent's hesitation, Undyne threw her spear, and then several more. Carmelita smirked and rolled out of the way. As she hit the ground, her pistol fired, a burst of electricity trailing up toward the cave's ceiling.

Undyne threw spear after spear, growling in frustration. No matter what she did, Carmelita would dodge, or roll, or flip out of the way. Undyne started throwing multiple spears at once, but it still wasn't quite enough.

She let herself get distracted. Far too late, she heard it – a chunk of rock, dislodged from the ceiling by Carmelita's seemingly accidental shot, was falling toward her. Undyne looked up, tensed, and jumped to the side. The rock smashed into the ground just next to her.

Undyne scoffed, satisfied. She turned – just in time to get hit in the face by one, two, three blasts of electricity.

Carmelita smirked. "What was that you said about not getting hit?"

Undyne rolled her jaw and spat on the ground. She returned Carmelita's smirk. "Alright, fox. Now you have my attention!"

Sly produced a bag of sweets from his backpack. "This just gets better and better." He opened the packet, then offered it to Papyrus. "Want some, pal?"

"HMM," he said, squinting thoughtfully, "WHAT'S THAT THING I KEEP HEARING ABOUT TAKING CANDY FROM STRANGERS...? AH YES! ALWAYS SAY 'THANK YOU'!" He took a handful. "THANK YOU!"

"No problem."

Undyne took a breath and summoned more spears – six which floated behind her, and one in her hands. Then she began to slowly stride toward Carmelita.

Carmelita backed up, wary of this new tactic. She raised her pistol and fired, but Undyne defended herself with her spear and continued to advance.

Suddenly, the six spears behind her shot upwards. Carmelita watched as they rose up, flipped around, and bore down on her.

She dodged left, but two spears cut off her escape. Two more came on the right, and the last two behind her.

She was boxed in.

Carmelita growled and fired at Undyne, but it was too late. Undyne was sprinting toward her, spinning her spear to block every shot. Without warning, she threw it. Carmelita had to twist awkwardly to avoid it – and then Undyne was upon her.

Carmelita dodged her punches as best she could. The spears hadn't faded yet, so she couldn't escape – only lean out of the way of Undyne's armoured fists. A kick to her leg took her by surprise. Her guard lowered – and Undyne summoned a spear.

The spear materialized right in front of Carmelita – it could have materialized through her, had Undyne wanted it. But instead, with pinpoint precision, the shaft passed through the trigger guard of Carmelita's pistol.

The magic solidified and Carmelita felt her hand being forced back. The pistol hung off the spear, just under the tip. Undyne grinned at Carmelita. She spun the spear, whacking Carmelita in the face with her own gun. Then she threw it, pinning it to the cave wall.

Carmelita growled and threw a punch. Undyne caught her fist. Carmelita punched at her with her other hand and Undyne caught that, too.

Undyne laughed and began to apply steady, crushing pressure to both of Carmelita's hands. "Now what, fox? Without your precious weapon, you've got no –"

Carmelita headbutted her in the mouth.

Undyne backed up a step, letting go of Carmelita. She seized the opportunity. She jumped into the air and twisted into a roundhouse kick, hitting Undyne in the side of the head.

Undyne grunted and fell back. Carmelita pressed ahead, moving in with another punch – and Undyne's hand shot out and grabbed her arm. "Nice try," she yelled, sinking a knee into Carmelita's stomach, "but I've," – she elbowed Carmelita in the jaw – "got the upper hand!"

She shoved Carmelita and the fox lost her footing. Undyne grabbed Carmelita by the leg and began to spin in place, swinging her around. She released her grip with a roar, sending Carmelita flying to the top of the cliff.

Sly and Papyrus jumped smartly to either side, dodging out of her way. She quickly got to her feet and ran to the cliff's edge – but stopped. This was a chance to tactically appraise the situation.

Undyne shouted from below. "Papyrus! Apprehend her!"

"OKAY!" he said.

Carmelita didn't turn around. "If you touch me I'll break your arm."

"OKAY!" he said. Undyne sighed.

Carmelita looked over the area. The spear which had pinned her pistol had now faded, and her weapon lay on the ground next to the cliff – but that was only part of the puzzle. She'd never admit it out loud, but Undyne was proving to be a bit too much for her, between her spears and her armour. She would need to strategize in order to come out on top.

Undyne growled, impatient. "What's the hold-up?! Are we gonna fight, or are you just gonna stand next to your boyfriend all day?!"

Carmelita bristled. "What did you just say?"

"YEAH, UNDYNE!" said Papyrus nervously. "WHAT ARE YOU IMPLYING? I ONLY JUST MET THIS WOMAN!"

Sly appeared at her shoulder. "Y'know, if you're getting bored of this, we could just slip away. Find a nice hotel, get a few drinks –"

Carmelita grabbed him by the his shirt collar, but her eyes never left Undyne's mocking grin. "Sly, I said I would save you from this woman, and she's not going to beat me. So you just stand here and be quiet and get saved, understood?"

He shrugged calmly. "You're the boss! … And then drinks, right?"

Carmelita ignored him. She took a few steps back, steeled herself, then burst into a sprint. She hit the edge of the cliff and leapt off, straight at Undyne.

Undyne laughed. "Yes! Finally! Now we're –" and then Carmelita slammed into her.

Carmelita recovered quickly – she had to if she wanted any chance of victory. She let out a flurry of short punches at Undyne's face, focusing her efforts near her eye. When Undyne backed up, Carmelita seized the moment. She grabbed her arm, swung her around in an arc, and planted a boot directly in Undyne's path. Then she released her. Undyne stumbled forward and landed in the water face-first.

She pushed herself up. "Seriously?" she said. "Your grand plan was to push the fish monster into the river?" She turned around leisurely. "You're going to have to do a lot better than –"

Carmelita was not where she had been.

Undyne tensed, looking around quickly. She soon found Carmelita –

– who had reclaimed her shock pistol and was pointing it right at Undyne.

Carmelita's eyes narrowed. "How's this?"

She fired.

Undyne roared in pain. The electricity was amplified by the water and surged through her armour, burning her. She lost her balance and crashed below the surface.

Carmelita strode forward, firing repeatedly. The river crackled as arcs of electricity coursed through it.

"WHAT?! NO!" yelled Papyrus. "UNDYNE CAN'T LOSE! SHE'S UNBEATABLE!"

"I would've said the same thing about Carmelita," said Sly, smiling proudly. "Sorry. Guess this might come as a bit of a... shock."

Papyrus said nothing.

Then he started to scream, and did not stop.

Ignoring the shrieking skeleton above her, Carmelita came to the river's edge. She finally stopped firing, allowing the water to settle. She scanned the river for movement, but saw nothing. After a few moments, she let out a sigh, allowing the toll of the battle to finally seep in. She sagged a little, but remained tall.

Carmelita turned and began to trudge toward the cliff. She looked up and saw Sly beaming at her, awe and pride in his eyes. Despite herself, she smiled back. The moment was only slightly ruined by Papyrus' ceaseless wailing.

The moment was conclusively ruined, however, by the spear that exploded through Carmelita's pistol.

She started, staring down at her mangled weapon in shock. Then she whirled around, fury blazing in her eyes.

Undyne rose to her full height, water running down the pathways the electricity had warped and twisted into her armour. Her gaze was fixed on Carmelita.

Papyrus recovered. "AAAAAAAAAAAAAAAAAAAAAAAAAAAAA-HA! I KNEW SHE HAD IT UNDER CONTROL! NEVER DOUBTED HER FOR A SECOND!"

The damage to Undyne's armour was restricting her movements. Without looking down, she reached up to her neck and dug her fingers into her chestpiece. She tore the armour off her torso, leaving just a black tank top.

Sly blinked. "I'd be lying if I said I hadn't hoped things would go in this direction."

"WHAT?" said Papyrus. "YOU WERE HOPING UNDYNE WOULD JETTISON HER ARMOUR, THEREBY SACRIFICING HER DEFENSIVE ADVANTAGE FOR GREATER MOBILITY?"

"... Yes," said Sly.

"OH. OKAY."

Carmelita snarled and flung what remained of her pistol at Undyne's face. Undyne calmly reached up and grabbed it – but Carmelita was already running for her. She tackled her and both fell into the water.

Undyne closed her forearms over her face as Carmelita rained down punches on her head. Her eyes were wild. "No! One! Breaks! My! Gun!"

Undyne brought her foot up and kicked Carmelita in the stomach, knocking her back. Carmelita hit the ground and rolled, growling.

They both stood. As Undyne strode out of the water, the armour around her legs fell away, leaving her in simple jeans. "Is it finally starting to sink in? You can't beat me into submission. No-one can. I am full to the gills with determination – and I never. Give. Up!"

Carmelita met her gaze, unflinching. "Yeah? Well, neither do I. So I guess one of us must be lying."

Undyne barked out a laugh. "I guess so!" She grinned, her eye narrowed. "Let's find out, shall we?"

Carmelita rolled her shoulders, fists raised. "After you!"

Both lunged.

It was eight and a half hours later.

Sly had thought he could never get tired of watching Carmelita fight, but apparently even he had his limits. They just kept going and going and going. Once Undyne got too tired to summon spears, and Carmelita became too fatigued to pull off any acrobatics, their brawl became a long, slow war of attrition – a question of which one would succumb to the other's endless barrage of increasingly pathetic punches.

Neither, it turned out.

Hard as it was to believe, the fight had become boring – and Sly did not take well to boredom. Papyrus wasn't faring much better. Despite his repeated claims that THE GREAT PAPYRUS was EVER VIGILANT, Sly had noticed the skeleton had become steadily crankier and less talkative. By now, he was leaning against the rock, clearly asleep.

And yet, below them, Carmelita and Undyne were still trading slow, weak blows. Sly knew he needed to put a stop to it. Leaving the crown balanced on the rock, he slid down the cliff to their level.

"O-kay," he said forcefully. "We all had a lot of fun today, but let's maybe call it here before one of you dies from exhaustion."

Undyne's breath was ragged, but even still, she grinned. "The only one... who's dying... is you! When... I kill you...!"

Carmelita copied her. "You're the exhausted one...! From... always being... wrong... all the... all... the..."

In perfect unison, they both collapsed.

Sly sighed gently. "Okay. I guess we'll just call this a draw, huh?"

Sly bent down to Carmelita. He wrapped her arm around his shoulders and helped her to stand, supporting her weight. "Let's find you some place to sit down, okay?"

"You're all going to jail," Carmelita mumbled sleepily.

"We sure are," he said, sympathetically patting her arm. "Whatever you say."

"Mmph."

He looked over to where Undyne was lying. "Gotta hand it to you, Captain. You really are something else. The kingdom's safe with you around." He smirked. "I won't be stealing anything else from around here – not unless I have a lot of back-up."

He turned away from Undyne's unmoving body and began to slowly walk Carmelita away.

Then Undyne's hand shot out and grabbed his leg.

Sly started. He managed to look down without yelping. Somehow.

Undyne was grinning manically, her sharp teeth on full display. Her eye was twitching. "I," she hissed, "will bite your ankles off...!"

Carmelita's eyes snapped open. "Round two!" She shoved Sly aside and fell upon Undyne – that is, lost her footing and collapsed, happening to land on Undyne's back. Both wheezed and grumbled and flailed on the ground.

Carmelita's sudden yell had startled Papyrus awake. "NYEH! EVER VIGILANT! VERY GREAT! WHAT?"

He looked around, getting his bearings. He watched Sly standing next to the two women, scratching his neck and wondering how best to break them up. Papyrus' eyes wandered away, and he noticed the rock next to him – with Asgore's crown sitting atop it.

This was what he'd been training for.

This was his opportunity to prove himself.

This was his chance to shine.

He grabbed the crown and ran away.

"AND THAT'S HOW WE, THROUGH OUR COMBINED EFFORTS, VALIANTLY RECLAIMED YOUR STOLEN CROWN!"

From his throne, Asgore stared at them both – Papyrus, standing proud, and Undyne, staring exhaustedly at nothing and swaying slightly.

He blinked. "... Golly."