The Run And Go by Twenty One Pilots.
~~~

"The Hidden Caves came from the Hidden Palace, curated by my tribe as a secondary place for the Master Emerald if Angel Island got attacked." Knuckles explained, guiding his friends through the beginning networks of the caves, Comlink light illuminating the space.

Amy eyed the dark (almost navy blue) rocks beside her. "If that's the case, why hasn't the Master Emerald retreated here when Eggman attacked?"

"You have to destroy it. The pieces will come here ready to be rebuilt."

"Have you ever been here?" Tails wondered.

Knuckles frowned at an array of purples and yellows mixing with the white light. "Not all the way through. But I have explored from time to time. It's more like a maze than a palace. Never saw a Chaos Emerald here."

"Hey guys?" Amy stalled, shrugging off the glowing backpack to pull it open.

There, the three Chaos Emeralds glistened and pulsed, giving a soothing hum. At least, to three. Sonic found it chilling, the way they seemed to tease and ridicule and deny any air to his lungs.

"We must be close." Tails noted.

"Wait, I think being here's making them like that." Knuckles estimated. "This place has to be filled with Chaos Energy- it's gotta be energising them."

"Then let's use that to find the next one!" Amy chirped and took the lead, winding and twisting down narrow paths.

"Be careful!" Tails warned. "There could be-!"

"Woah!"

Rock crumbled beneath her boots and Amy tumbled forward, squealing at the bag dropping towards the great expanse beyond. A tan arm wrapped around her waist and the other reached for the Chaos Emeralds, narrowly gripping a strap as they pressed against the cliff-face.

Looking up, she nervously smiled at Sonic who held her and Knuckles who clung onto the speedster's ankle, all lifted by Tails with strain evident on his face.

"You're so heavy!"

"That's because I'm all muscle!"

"You okay?" Sonic asked, softer voice catching her attention.

"Y-yeah."

As Tails set them down, Sonic hummed. "Good. We cant lose you or the Chaos Emeralds."

"Ah. Yeah."

"Woah." Tails disrupted, guiding the others towards the tremendous dug out space.

Water poured in from the rocky walls, slipping down dark stone to create a ring below. In the middle, light teal concretion and wonderful, aged purple pillars gave a home for the many Chao that flew and sung. They weren't aware of visitors and continued with their dance without a care in the world.

"I've never seen this before." Knuckles breathed.

"It's...beautiful." Amy gaped.

Sonic turned to her, captivated with how the Chaos Emeralds' light washed over her. "Yeah, sure is."

"We'd better get moving." Tails urged, taking the backpack and only managing to slip it on with a few steps forward when a few arrows flew right by his head.

If it weren't for Sonic yanking him back...well, it made the group tread forward with more caution. It seemed setting off the first trap awakened all the others, for the four found themselves in a sprint shortly after.

"Is it always this fortified?!" Amy bellowed, dropping to her knees to slide beneath a swinging log.

"Not in the other caves I've been too! This one must lead to the Master Emerald hideout!" Knuckles leaped off the thin edge of cliff they had, gliding around to avoid blasting torches.

With the expanse left behind, they were forced to stick to the walls and even there traps protruded out from the stone. Tails felt the chill of moving, shutting rocks close from behind and yelped from his namesakes almost being snapped off- fortunately he lunged and caught himself in the air ahead.

"It's been a while since I've moved like this!" He whined, hacking up dust when a cobalt blur blasted by.

The spiky sphere bounced around the rocks (gathering twirling golden rings), sliced through pincers and broke down tumbling boulders, slipping by more flames before unravelling in a small clearing. Cartoonishly, Sonic cheered with arms in the air, meeting three very flat expressions.

Until Amy's eyes widened. "Sonic! Look out!"

He whirled to the uphill ahead where massive boulders rolled down. A log came from behind and with a yelp and jump Sonic took off. Amy summoned her hammer and with Knuckles bashed the rocks in their wake, making a path for Tails to wind passed. Rounding the blazing corner they met Sonic stumble and stall, a few spines cutting from his head upon a saw zooming by.

"You okay?!" Amy called, crushing her hammer over one of the remaining grey spheres.

Sonic huffed and combed through his quills. "Nothin' I can't handle. You guys alright?"

"Not yet." Tails gulped and pointed ahead.

Swiping sweat from his forehead, Knuckles gaped at the swinging weapons, smashing logs, licking flames and crushing and opening walls.

"Okay Team." Sonic stretched. "Up for a challenge?"

"Together?" Amy swung her hammer. "Walk in the park."

"The traps go about every six seconds." Tails calculated. "How can we go around that?"

Sonic grinned, fingers pressing against the gravel. "We aren't going around."

"Oh no." Knuckles mumbled.

"We're going through."

When he blasted forward, he took Tails and Amy by the hands, letting Knuckles grasp onto the pink hedgehog as everything around became a dizzying blur. With boulders slipping out the sides, Amy swung as many away as she could before feeling her hold slip away. Sonic had done so in a way the three spun.

"Up ahead!" He called, gesturing to the green light pouring at the far end.

Thus, he bounced towards Knuckles who sent a hit for the, then, splintered log and another at him to zip by. The echidna followed as Sonic crashed into Amy's hammer, immediately getting pummelled upward. Knuckles scooped the pink hedgehog up, gliding forward, and Tails caught Sonic's reaching hands, the two becoming a blur as they stampeded ahead.

"Look!" Amy gasped.

Before the opening, crumbling walls began uprooting from their dormant state. Faster than expected, Sonic yelped in surprise when he was again knocked forward by Amy's hammer. Tails shrugged the backpack off and slung it across the ground like a disc, meeting Sonic on the other side.

Knuckles caught his best friend unravel (black mist creeping around his ankles) before the walls disrupted his view. With a gruff exhale he punched his fists together, meeting the blockage with Amy's weapon, bringing it to pieces. Tails spun his namesakes after, sending terrible gusts of wind to the flames to clear a path.

"Woo! We did it! Hey, Sonic, we-." Amy's words fell silent when her eyes met the great space beyond.

A glistening, charming keyhole passage. Limestone ground and sparkling water, the silence broken up with droplets from dripstones above. The expanse was illuminated by sunlight through the gap, casting over a mossy mound with eight, circular holders on top. Purple in colour, they were cracked and aged and one was much larger than the rest.

"Is this...?" Amy hushed.

"It looks like the Chaos Emeralds go here too." Tails answered.

Sonic stepped from his friends with the bag in hand, meeting the mounds surrounding pond. The sight he met made him violently ill and it took all his willpower not to vomit. His eyes were scratched out, black mist covering them, and his lips were sown into tight stitches. Glowing, terrifying, white eyes peaked over his shoulder with an even nastier grin. Scrawny, grey arms slipped around his front and Sonic could feel the weight of them press against him.

It wasn't real. It wasn't real. It...it wasn't real.

"Hey, Sonic?"

He pried his eyes away and the heaviness left, paralysing fear twisting into curiosity at Tails' call. On the other side of the pond, his three friends awaited beside rather detailed pictographs. Thus, Sonic climbed over treacherous terrain and swung his legs forward to land, nearing the group. There, he fixated on the inscriptions and eyes widened.

There were Chao and odd stone-like creatures similar in shape, on opposing sides, with paws reaching to each other. Above, and what really had his attention, was the drawing of multicoloured hands reaching for a mighty, terrible moustached machine and-

"Sonic, is that...you?"

—————

Vector Crocodile probably should be happy with little cases coming in, but with rent forever climbing the ladder he'd even take minor theft reports to investigate. Yet, when he asked for something similar last time the Chaotix found themselves-

The phone called, and the number was very familiar.

He set down some paperwork and removed his headphones, reaching over as a young bee peaked around the doorway- legs strained on the bottom step.

"Who is it?" Charmy Bee asked, pouting when his boss waved a dismissive hand.

"Hello?"

"Ah, Vector, hun, you busy?"

"Rouge? No more than usual, why?"

"Business still slow, huh?"

Vector's face flushed. "Not noticeably!"

"Well, either way, I've got a favour to ask."

"Oh yeah?"

"I need you three to look into Eggman for me."

When Espio reached Charmy's side, he gave a perplexed look but was only met with a shrug.

"Eggman? He makin' an appearance again?"

"That's the thing. It's actually his lack of action that's got me concerned. He's set up on Bygone Island and when we went he didn't even seem to acknowledge us."

"Was Sonic there?"

"Yeah."

Vector frowned. "Huh. 'Was sure that would get 'im to do somethin'."

"Either way, you in? I'll fill in the gaps on the way."

"You can count on us!"

"Glad to hear it, hun. You'll have some friends waiting out for you there."

———

"Knuckles told us stories about the Chaos Emeralds once. Even he had the impression they were just a myth." Espio conversed.

Vector dropped his wave and turned away from the G.U.N helicopter. "Well apparently they're real. And dangerous-."

"And Eggman has one." Charmy reminded.

"Yeah. And Eggman has one."

Espio frowned, brushing by some palm trees. "There are seven, yes? Why only go after one? If he's managed to find it so quickly surely the others would come easier."

"Maybe he's waiting for Sonic and our friends to get them first." Charmy shrugged.

"That is-...that is actually plausible."

"Hey, either way, I think I've found our tour-guides." Vector disrupted, giving an unsure but polite wave to an albino hedgehog, purple cat and brown badger.

"Are you the Chaotix?" The badger gave a suspicious glance over.

"That's us!" Charmy buzzed. "And...y-you are-?"

"I ain't givin' my name to strangers!"

The cats eyes rolled and she gave a gracious bow. "I am Blaze. This is Silver and Sticks."

Sticks dramatically gasped and glared. "Traitor."

Going ignored, Blaze gestured for the detectives to follow- allowing the badger to lead.

"Nice of you to join us, but, how did you get here so quickly?" Vector inquired.

"Shadow is not the only one who can bend to where he needs to be." Blaze replied.

"Huh-?"

Silver nudged her. "Go on."

Weirdly, she became tense but managed to oblige and wave a hand. Despite her protectiveness, seven rectangular emeralds formed around her head.

"These are the seven Sol Emeralds. With my pyrokinesis, I can use them to my will."

"Oh wow. That's amazing!" Vector grinned.

"How come you can use them?" Charmy questioned.

Blaze brought the jewels back into the confines of nowhere and her tail sharply flicked. Despite her rising shoulders, her ears were low.

"I am their Protector."

"So like Knuckles." Espio responded.

"In a way, yes. I suppose we were both born into such roles."

"Rouge said two of you are not from around here, I am assuming it's you two?"

Silver nodded. "From two hundred years into the future. Blaze is-."

"Sol. I come from Sol. Another reality."

"Why leave it?"

When Blaze's hands curled into fists, Vector worried he'd pushed too far. Silver took her hand in his and gave a squeeze, offering a gentle smile.

"It...was not by choice."

"Oh." Charmy dropped to walk with the group. "I'm sorry."

"Silver came to me when I-...he needed help and eventually we left together."

"It sounds like you've both had it hard- I hope being here makes it easier." Vector empathised.

Blaze came to a stop, examining the sand and trees and seashells. Despite a lack of ships, it was familiar. Mobius was much more connected, in many ways (just like hers), and those she knew were easily recognisable too. One in particular stood out to her.

She hated it.

Silver however took in their surroundings too, but his face was with awe and intrigue. He drunk up the sunlight, Flickies and waves. No more dark sky, acidic rain, burning oceans or fiery creatures.

He loved it.

"It's amazing to see what Mobius was once like. In all the tries we've made, we've never been able to stay long enough to really take it in. Besides, they were never this...."

Vector grinned. "Free?"

"Exactly."

Blaze tightened at the word and looked to the group. "Is that because of Sonic's efforts?"

"Well I wouldn't say just him but yeah-."

"And is he, himself, free?"

Espio raised an eye ridge. "What are you leading towards?"

Blaze's arms crossed. "I've just never...."

Could it be possible?

No. Why would Sonic be running off so much? Hers wouldn't steer so far away from his friends, even if he curated his own path. He wouldn't lie, so plainly, and slip into even deeper mistruths.

But he still had that same grin. That same confidence and relentless optimism. A light so great he taught her how to trust again. A stubbornness so unwavering he convinced her to lean on others, broke her walls and made her laugh again.

Perhaps this Sonic had lost his way. Maybe she could try and....

She shut her eyes and turned to the side. "Never mind. Apologies. Forgive me."

Vector's eyes widened. "Hey, relax. We-."

"You guys!" Sticks interrupted, bursting from the trees to near the group.

"Everything alright?" Espio asked as Silver hooked arms with the feline.

"I'm not sure. Unless Eggman has a massive chimney, is it normal for smoke to be comin' from his base?"

———

"It's weird, he hasn't really attacked us much- only doin' so to keep us in check. I jus' thought he was busy with the Chaos Emeralds." Sticks rushed out, weaving vine to vine from above.

"When did you say Eggman came and took your Chaos Emeralds again?" Silver wondered.

"He only got one. I 'ad the other. Cliff had one, which was taken, but that was before he came to see you guys."

"Which was about a week ago." Blaze frowned.

"So...he set out like a week before that. Two weeks, then."

"And nothing since?" Vector sighed.

Sticks sweat-dropped. "Not a peep. That's...weird, right?"

"He has disappeared for an entire year before." Espio reasoned. "But he was reclusive- away from all civilisation. I'm surprised we haven't heard anything sooner, considering his location."

"There wasn't anythin' to say."

"That's my issue."

Reaching the shore, Silver dug in his bag and pulled out some strange binoculars. At least, that's what the Chaotix assumed they were. Blue in colour, they were two small rectangular pieces the albino slipped over his already strange contacts.

"Woah." Silver gaped.

"What is it?" Charmy urged.

"It's...Eggman's base is...it's not even completely built! From here, it looks like the opposite. But with better eyes you can see the cracks! It looks like he's been attacked at some point!"

Blaze paled. "If that is the case, who has the Chaos Emerald?"

—————

"Whoever it is, they have style." Sonic tried a grin, hands resting on hips.

"Is that the Master Emerald?" Knuckles' eyes widened and he traced a hand across the pictograph.

"This is incredible! Who knew Sonic and Eggman were prophesied!" Amy gazed.

"I wouldn't say we're-." When red light cast over the inscriptions, Sonic's quills raised and he slowly turned to find the ruby Chaos Emerald floating above the pond.

"No matter how many times we find one of them, they always surprise me with how beautiful they are." Amy stepped towards the jewel, summoning her hammer on instinct when the rocky ceiling shook above.

"We should get it quickly and leave." Tails stressed, namesakes spinning.

Sonic groaned, a strange ache in his head blossoming as he reached to his muzzle, the beginnings of a nose bleed present. He barely noticed Knuckles hurry to his side, muffled concern drowning out from the crumbling walls.

The headache felt separate from him reaching closer, somehow. Dangerous smile and beastly claws, yet Sonic pushed through to throw his friends behind him when the headaches source crashed through the expanse's gap.

Steely, cold red optics. White, glowing sclera. Metal versus organic claws. Blue form and black fur. Sonic's vision wavered as shiny red shoes touched the ground.

Darker in colour, with pointier 'quills' in the shape of a star and black shoulder plates. White streaks ran across such spines and a firm but bendy cape flowed from his waist. Taller, sharper and through their connection, he could tell, angrier.

"Sweet Gaia...." Knuckles murmured.

'Surprised to see me, Sonic?'

Since when could he-?

'How about that rematch you promised?'

And Metal Sonic lunged.