Neon lights flashed on the empty streets of City Zone 1. Tails was grateful for the lack of crowds as the motorized sidewalk carried him and Sonic under the blood-orange sky, the smog hiding the sun and floating billboards obscuring what little sun rays made it through so night never seemed to end.

"The name's Sonic the Hedgehog, no family name, or well, I probably have one but I don't really remember my folks so I couldn't tell you what it is—"

Tails sighed, annoyance filtering through his face while red and blue lights from a clothing shop window advertising Eggcessories dyed his fur green and orange.

"I'm seventeen by the way. My birthday is on June 23rd though, so I'll be eighteen in a couple weeks. And you…you're what? Seven? Six?"

Tails' teeth grind together, but he couldn't let the hedgehog know how much his talking was getting to him. Besides, listening to the hedgehog's rambling had at least helped him learn this Sonic had lived a life eerily similar to the Sonic of this world.

"You know, now that I'm almost all grown up, I've been reflecting, looking back at all my adventures…I think my best one began on West Side Island."

Tails stiffened.

"I was searching for Eggman when I spotted a couple of jerks picking on some two-tailed kid."

The kit bit his tongue and just barely reined in a scream.

"So I taught those boneheads a lesson and kept it moving, but then I noticed this shadow following me. I look back, and it's that kid, but get this, he's flying. And not only that, he's actually keeping up with me! It was the coolest thing I'd ever seen. That…that day might have been the best day of my—"

"Would you just shut up!?"

Tails whirled around, fists clenched, and Sonic recoiled in the eggclosure. However, the pair of otters on the adjacent sidewalk kept their eyes firmly on a toy store and the raccoon behind them stared blankly at the ground.

"You can tell me your life story," Tails' voice trembled with rage, "After we get to the interrogation center."

Sonic blinked. Yet soon a self-satisfied smirk curved his mouth and Tails jolted as he realized what the hedgehog had done. He'd gotten a reaction from Tails, confirming that he'd met his Sonic in a similar way to how this Sonic met his Tails…and this wasn't the only time he'd done that, was it?

Sonic hadn't been rambling. He was purposely throwing out facts and watching Tails' reaction to see how similar this world was to his. That…was actually pretty clever…

"Sorry," Sonic said in a tone that very much implied he wasn't, "I was just talking to distract myself from the fact the sky looks like poison."

He glanced up with a frown, then gestured towards the city streets. "And how everyone here looks like they have clinical depression."

To emphasize his point, Sonic waved toward the raccoon behind them. The woman briefly raised her dull eyes. Recognition sparked in her gaze and her mouth fell open. However, she quickly noticed Tails.

Her eyes snapped down, hands clutching her purse strap and body language begging him to look away. Tails frowned, though he was used to the reaction, he still didn't enjoy inciting fear. Yet the kit quickly brushed off the feeling and glared at Sonic.

"Nobody is depressed," Tails huffed. "It's not like we forced them to live in City Zone 1. We just offered people residence and they came."

Sonic raised an eye. "Was that offer made before or after Eggman devastated the rest of the world so much that his City Zones are basically the only places normal people can survive?"

Tails glowered, but instead of answering, said, "Also, it's not that polluted." Sonic's eye rose even higher, and Tails snapped, "It really isn't! These days, most City Zones have air filter bots cleaning up the atmosphere. We just haven't gotten around to putting them here yet."

"So bots that produce pollution," Sonic said skeptically. "Are cleaning up the pollution?"

Tails bared his teeth. "They run on solar power."

Sonic paused, taken aback. "Huh." He scratched the back of his head, muttering. "Never thought I'd see the day where ol' Egghead went green, but then again." He looked intently at the fox. "Never thought I'd meet a Tails who worked for Eggman."

Tails' brow furrowed. Why did this Sonic sound like he'd met another Tails before? Just how many times had he traveled to another reality?

The sidewalk stopped. Tails looked up to see an enormous, golden egg-shaped building hovering hundreds of feet in the air. Silver railings were wound around the egg with robotic police officers patrolling upon them and searchlights shining all over the egg's exterior.

Sonic gaped at the prison while Tails walked under the giant building with the eggclosure following. However, the hedgehog's expression grew deadpan as they stopped under the building's shadow and the fox clicked his wristband twice to activate the entrance.

"No, Tails, I think you're right," Sonic said dryly. "This place is clearly not a dystopian wasteland ruled by a man with an ego about the size of this building. I mean who wouldn't want to live under—"

"Silent mode activating."

Sonic froze. He eyed the eggclosure as the forcefield darkened from blue to green.

"What is—"

Sonic's mouth moved, but no sound reached Tails' ears. The fox sighed in relief while a red tractor beam shot down at them from the egg. Tails and the eggclosure lifted off the floor as the building's underside pulled apart with a mechanical hiss, and they were quickly carried in.

Bright overhead lights and a gray circular hallway greeted them as the doors closed under their feet. The tractor beam shut down and Tails landed on the spotless floor while the eggclosure dropped beside him, Sonic looking around the area.

Tails turned to the hedgehog and smirked. "This is the Egg Dome, the largest prison in the Robotnik Empire, and since you're feeling so chatty, why don't we visit the interrogation center and you can tell me all about your life...while you still have one."

Sonic's eyes widened, and Tails' smirk only grew.

Sonic was thrown out of the open eggclosure and grunted as he landed roughly on his hands and knees. Yet he couldn't stand before chains with pincers shot out of the walls and snapped around his wrists and ankles.

"H-hey!"

The chains lifted him five feet above the floor and splayed out his limbs.

"Is this really necessary—gah!"

Blinding light beamed on Sonic's face and he flinched, eyes squeezing shut while Tails went to a computer on a silver podium in the center of the room. He waved his wristband in front of the screen and the computer beeped.

"User Recognized," a robotic voice said. "Welcome, Tails."

Sonic's vitals alongside a thermal image of the hedgehog appeared on the screen.

"Oh, come on! I already said I'd tell you whatever you want to know!" Sonic struggled against his restraints. "So what's with the bug under a microscope treatment? Hedgehogs are mammals, not insects!"

Tails glared over the computer. "The mechanical arms are monitoring your vitals to make sure the treatment doesn't go too far."

"Treatment?"

Sonic's expression twisted with confusion, but his ears shot up as a gold laser cannon dropped from the ceiling and aimed at his head.

Yet soon the teen groaned, tone unimpressed. "I repeat, is this necessary—"

"How did you get to this world?"

Sonic's mouth clicked shut. His expression grew serious and Tails' eyes narrowed when Sonic's pulse spiked on the computer.

However, soon Sonic's heartbeat eased and the hedgehog relaxed as much as he could with his limbs suspended.

"Well, that depends," Sonic glanced at the cannon, "Am I going to be shot if I don't explain everything perfectly? Because I know how I got here—"

Surprise flared on Tails' face.

"But I'm no expert in reality-hopping," Sonic shook his head, "So if you want me to explain in scientific terms how I got here, you're going to be seriously disappointed."

Tails glanced at the computer. Sonic's heartbeat hadn't changed…he didn't seem to be lying.

The fox looked up. "No, you won't be shot, just explain what happened and leave the science to me."

Sonic brightened. "Great, I knew you'd be a pal!"

Tails' expression soured while Sonic hummed, eyes drifting up to the ceiling.

"Now where to start? Well, I guess it began about four months ago. I was chilling at my beachside house, reading a good book, sipping on lemonade, and just enjoying my retirement—"

"Retirement?" Tails' face scrunched in confusion, and Sonic grinned.

"Yeah, I retired from heroing." Sonic shrugged. "Eggman's not around to cause chaos anymore—"

Sonic's blood pressure rose a few digits before quickly falling back down.

"And while the world's not perfect, no one's really been that much of a threat compared to him… Also, I just haven't felt up for an adventure since…"

His eyes glazed over, face falling. "Tails…"

The fox's muzzle twitched uncomfortably, but soon Sonic shook his head and hung a smile on his face, though it was crooked. "Anyway, this meteor thing crashed by my house. I went to investigate because I didn't want my place catching fire and I found this glowing crystal…"

Tails' brow rose, but he simply glanced at the computer. No abnormalities, so the hedgehog was still telling the truth.

"Then I heard this voice." Sonic's smile fell, gaze growing distant. "It—I know this is going to sound crazy—but it sounded like…" He frowned and looked straight at Tails. "It sounded like you."

Tails blinked. "Me?"

Sonic's eyes shifted aside and he bit the corner of his mouth. "Yeah, or well, it sounded like my Tails, but I knew that was impossible. Still, he sounded sad… I couldn't just ignore it, so I reached out and touched the crystal. Next thing I know, I'm seeing space, literally, and things are spinning crazy fast, which is normally my style, but this was even too freaky for me."

Sonic glanced at the ground, face wrinkling like he was thinking hard. "I fell unconscious, and when I woke up, it soon became apparent I was in another reality. I thought I'd be trapped there forever, but then…"

He grimaced, glanced at Tails, and hope tinged his gaze. "I heard Tails' voice again, and it led me to another crystal."

The fox's eyes narrowed. "This voice told you where the crystal was?"

Sonic shook his head. "No, I couldn't really understand Tails, his voice kept overlapping like he was saying three different things at once. But he always sounded closer, got louder when I was near a crystal."

"So you used the sound of his voice to find a crystal?" Tails asked, checking his vitals.

Sonic nodded. "Yeah, and this time I played it safe. I cut off a sample from the crystal, wrapped it up in a cloth, and carried it with me for a while. Of course, I eventually landed in some trouble, so I touched the crystal and it sent me to another reality."

The hedgehog frowned. "And, uh, that's pretty much what's happened to me again and again ever since the crystal crashed on my world."

The heart monitor spiked on the computer. Tails watched it remain elevated, but that didn't necessarily mean the hedgehog was lying, so much as he might be leaving information out. However, Tails had heard all he needed so he wasn't too concerned if some details were left out.

"Okay," Tails looked up, "So you don't have the crystal on you anymore, but you can find it if you start hearing…what you think is Tails' voice?"

The kit grimaced, feeling a bit weird referring to someone else with his name.

"Pretending I don't hear the strongly implied 'you're crazy, Sonic,' yes, that's the gist of it."

Tails' expression became thoughtful. In that case, he could use Sonic to find the crystal and then examine it for himself… If he could somehow harness the crystal's powers and present it to Dr. Robotnik….

"Why are you working for Eggman?"

Tails started. He looked up to see Sonic gazing at him seriously.

"I was being honest when I said I've never met a Tails who worked for Eggman. An Amy working for Eggman, sure, and Knuckles sometimes too, but you, Tails…"

Sonic's face drooped, words ringing with disappointment. However, the fox glowered.

"You're not the one who gets to ask questions," Tails hissed.

Yet the hedgehog's gaze sharpened, a calculative look coming upon him. "He hurt you."

Tails growled. "Stop doing that."

"Was it something he said?" Sonic persisted, green eyes narrowing. "Or did? A betrayal?"

Tails' hands balled up into fists. "I said stop—"

"Broken trust? No, no, broken promise—"

"And how was your Tails feeling when you let him die!?"

Sonic froze, eyes growing big and round. Tails' chest heaved, wrath lining every inch of his face while his question echoed through the air. However, Sonic continued staring at him, a sheen coating his eyes, and Tails balked as he realized what he'd said.

Tails' mouth moved, but he didn't know what to say, and couldn't think of anything as Sonic exhaled shakily.

"Tails," Sonic whispered, voice cracking while his head bowed. "I let him fly too soon, my mistake."

Tails flinched, recalling the same guilt in Sonic's letter.

"Don't blame yourself for what's happened, that's my fault, not yours."

The fox inhaled sharply while Sonic raised sad, empty eyes.

"I don't need you to tell me what happened," Sonic said, suddenly looking very tired. "I already know why you're with Eggman." He sighed. "Your Sonic made a mistake and you paid for it…because no matter what reality it is, I'm always an idiot."

His face wracked with guilt. "So whatever he did, I'm so sorry."

Tails' breath hitched, the sincerity in Sonic's voice making something in his chest crack. But…but who cared if this Sonic apologized? Sorry didn't change the past…and he was probably just saying it to manipulate him, use him. Because all Sonics were liars, that was the truth.

The ground shook, lights above swinging with the tremor. Tails yelped, glancing up as the entire building shuddered and electricity sparked along the walls.

"What?" Tails whispered as the lights shut off and on.

He turned to the computer and quickly started typing on the keyboard. The security feed popped up on the screen, showing other hallways in the prison where badniks lay unmoving on the ground. Some videos were even black like the cameras had been cut off.

"The Resistance," Tails hissed. "They're attacking. But how did they get past the patrols?" he asked himself. "The badniks are specifically programmed to attack any unauthorized organics."

"Who says we're organic?"

Tails jolted, gaping at the talking computer. No…the rebels couldn't have…

"We've taken over Zone 1's mainframe."

Tails took off into the air, teeth gritting while he soared towards the door.

"Tails?" Sonic called, worry wrinkling his face.

The fox ignored him as he waved his wristband in front of the entrance. The door stayed shut. Tails growled and slammed his fists against the metal, the bang echoing.

"You cannot keep our hero."

Tails' eyes widened while the building shook again, pieces of dust and metal tiles dropping around him.

"The Egg Dome will fall."

"Tails!"

The kit's head whipped around to see the laser cannon was no longer facing Sonic, but himself. It fired, laser shooting towards him, and Tails flew back, but then the world tilted.

The laser grazed Tails' left arm. He screamed as fiery pain sparked up his old scar while the Egg Dome groaned, tilting towards the city beneath them—the boosters were failing.

Tails fell to the ground, eyes screwing closed as he slid down the smooth black floor. He weakly tried to catch himself, but his arm was screaming while debris clattered around him.

"Tails!"

His head crashed into the wall and a ringing pierced through his brain as everything went black.

Tails woke up warm—too warm. He cracked open his eyes and squinted against a faint blue glow, lifting his head.

Hundreds of wires layered on top of each other formed the dark circular tunnel Tails laid in. The fox's eyes widened. This was the Egg Dome's core, where the CPU was stashed.

Clicking on a keyboard pricked Tails' ears and he turned slightly. Sonic was facing the giant computer at the end of the hallway, fingers moving deftly over the keyboard while code sprinted across the screen.

Tails paled. This Sonic knew how to code? But then he could take control of the Dome's CPU and that would give him power over the entire city.

The fox silently pushed himself up, barely noticing his lab coat was missing and that strips of torn cloth were bandaged around his head. He got to his feet and slowly started walking to the hedgehog.

Once he was only a foot away, Tails stopped and reached back, pulling out his stun gun. He should be close enough that not even Sonic could dodge his bolt. The kit took aim and his finger squeezed the trigger—

Tails was against the wall with a red and white shoe pressing on his chest faster than he could blink. He wheezed, the stun gun slipping from his grip, but Sonic didn't spare him a glance as he examined the computer.

"Is shooting people how you say thanks in this reality? Because if so, you're free to try again, but maybe after I finish rebooting the system."

Sonic stopped typing and cocked an eye toward Tails. The fox glared, grabbing Sonic's foot, yet not attempting to pull it off.

"So you do have super speed," Tails hissed. "And you know your way around computers." His face hardened. "But you won't be able to take over the city once reinforcements show—"

"Take over the city?" Sonic scoffed, and an easygoing grin came over his face. "I'm not taking over the city. I'm rebooting the system after that EMP knocked this giant egg out of the air."

Tails blinked. "What?"

Sonic went back to typing, fingers moving at super speed and lines of code flying on the screen.

"It looks like those Resistance guys hacked into Zone 1's mainframe and used it to unleash an EMP that knocked out everything electrical in the Egg Dome. I guess they heard you captured me, assumed I was the Sonic of this world, and decided to do this to free me."

"All the other prisoners would have escaped too," Sonic added. "But I managed to hook up your wristband's battery to the CPU and locked all the doors just in time."

The blue coding reflected in Sonic's eyes while he stopped typing. "So now all that's left is to reboot the system and we'll be back in the air."

Tails gaped. "You…you kept the prisoners in here?" He shook his head disbelievingly. "Why? Why didn't you just run and go find that crystal—"

"You would have been in a lot of trouble if all the prisoners escaped the Egg Dome, right?"

Tails' eyes widened. Sonic couldn't mean that. There was no way he'd done this for him. That was insane.

"Are you out of your mind?"

"Not according to my therapist," Sonic said breezily, yet his expression soon grew thoughtful. "Though I am a bit traumatized after everything I've been through and might have ADHD, I'm not too worried about that."

Tails blinked twice. However, his shock quickly crumbled into wariness. This…this must be a trick. Yeah, Sonic was just trying to gain his trust…even though that wouldn't benefit the hedgehog in the slightest.

"And done!"

Sonic hit the enter key and Tails' ears pricked as the generators whirred in the distance. The ground rumbled and Tails' stomach dropped as the Egg Dome lifted, a fresh wave of cool air drifting into the hall while air conditioning started back up. However, the lights didn't come on. Seemed they would need another minute.

"So," Sonic turned to him, expression serious, "I'm going to let you go and you're going to thank me by not trying to shoot me, sound good?"

Tails scowled. "This won't make me trust you."

Sonic smirked. "Or like me clearly."

Tails huffed. "Fine, I won't shoot you."

Sonic took his foot back and Tails landed on the floor. He brushed off his stomach fur and walked back to grab his stun gun off the floor. Yet he tensed as a clang resounded from the darkness ahead.

Wind rushed next to him and he turned to see Sonic staring intently at the shadows.

Tails frowned. "That couldn't have been the prisoners. The badniks should have come back online and taken any unregistered organics back to their cell."

Sonic gasped. Nervousness flashed on his face.

"Umm," the hedgehog rubbed the back of his head, "You wouldn't have happened to be using your wristband like a keycard to let all the badniks know—"

"I'm a registered user?" Tails sighed while another clang resounded from ahead, closer. "As a matter of fact, I was."

Sonic winced. "Ah, so—"

"A swarm of badniks is coming and will treat us both like criminals because it doesn't recognize me. Also, if they damage the CPU, this whole place could blow up."

Sonic smiled sheepishly, scratching his face. "Sorry about that."

Tails rolled his eyes and lifted his gun, aiming at the darkness as more clanging resounded through the air.

"Well, at least it's you and me, pal. Nothing can beat—"

A robotic centipede slithered out of the shadows, blood-red jaw opening wide as it stretched up to the ceiling and screeched. A blue blur launched straight into the centipede's chest and it toppled back, red eyes fading to black.

However, a second centipede crawled over its body, fire billowing from its mouth. Tails flew up, the flames rushing under him, and he fired at the centipede's head. It froze, circuits overloading from the stun bolt. Yet a dozen crablike bots crawled across the ceiling and Tails moved to shoot them.

Lasers flew all around Tails, close enough to singe his fur, but Sonic spindashed below and cut through the line of badniks. Tails gritted his teeth, trying to ignore the hedgehog and the sense of familiarity in the air. Yet his hopes were dashed when gloved hands suddenly reached for his.

Instinctively, Tails dropped his stun gun and caught Sonic's hands. He choked, a strange feeling coursing through him as those larger palms grasped his. However, he quickly shook it off and soared down the tunnel, Sonic's feet ramming into a few egg pawns and bowling them over.

"Strike!" Sonic called back with a smirk and Tails groaned.

Sonic's jokes were one thing he never missed… Not that he missed anything about that hedgehog.

"The door!"

Tails refocused and just made it out the door at the end of the dark hallway. It was closing fast.

Tails' eyes widened, but soon they narrowed. "I can make it!"

He pushed his tails to spin faster and the wind lashed against his face while Sonic shouted, "Woah!"

The doors only had a foot between them, but they were still a distance away. So Tails twisted his left ankle, and a rocket booster flared under his sole, shredding apart his shoe.

The wires blurred around them as they shot through the opening and the door shut behind them. Tails grinned, twisting his ankle to shut off the booster before Sonic noticed and slowing in the pitch-black hallway.

"Wow."

Tails looked down and saw Sonic staring at him with a wide grin. "You're already so fast."

Pride shined through his voice and Tails was taken aback by the tone. However, he soon recalled who this was, and his face hardened. He dropped Sonic and crossed his arms.

"This isn't the time to celebrate. We still have to get out of here, and considering the Egg Dome has forty-six floors…"

Tails trailed off, staring at the black wristband Sonic was holding up to him.

"I, uh, grabbed it before we got out of there." Sonic turned away awkwardly. "It's probably out of power, but it should still let all the badniks know you're a registered user, maybe?"

Tails suddenly noticed Sonic's goggles were glowing and on its side…something was written…

Tails the Fox. He gasped softly. Those weren't Sonic's goggles…they were his counterpart's…

Tails numbly took back his wristband, his mouth pressing together. Sonic perked up and started walking ahead, waving him after.

"Well, let's hurry out of here. I mean, you still gotta hook me up to that power grid, right?" the hedgehog asked far too cheerfully, and Tails' face twisted with confusion.

The kit looked down at the wristband in his grasp, staring at his reflection where bandages were wrapped around his head. Why…why did Sonic help him?

Tails looked up and spotted the faint glow from Sonic's goggles flopping in the distance. Why hadn't Sonic just left already?

The fox sighed, frustrated by the many questions surrounding the hedgehog, but he quickly flew after him. He hated how natural it felt when Sonic glanced back with a toothy grin, but more than that, he hated that some part of him glowed at Sonic's open adoration.

Tails didn't trust him—he knew better than that—but the hedgehog hadn't left even when he could, and something about that smoothed over a scar on his heart, which Tails hadn't even realized he had. Of course, all Sonics were liars, and nothing the hedgehog had done so far proved otherwise. Yet maybe not all Sonics would just leave Tails behind the second they could.

Tails glanced at Sonic's goggles. His face fell.

Even when they should.

Thanks for all the support, everyone! I hope this chapter has only fueled the fire behind your theories of Darker!Sonic's backstory, though I have to warn you, I'm known for my plot twists ;)

Anyway, feel free to theorize/comment below!