Chapter Text
The entrance to the abandoned facility yawned open like a broken jaw, rust bleeding down its metal frame in long, orange streaks. Sonic stood at the threshold, arms crossed, one foot tapping impatiently against the cracked concrete.
"You know," he said, tilting his head toward Knuckles, "for a guy who's supposedly a genius, Eggman sure picks the creepiest real estate."
Knuckles didn't look up from examining the door's hinges. His violet eyes traced the damage with intense focus. "It's been abandoned for months. The structural integrity could be compromised."
"Aw, c'mon, Knux. Where's your sense of adventure?" Sonic grinned and tapped the side of his head where the communicator sat snug against his ear. "Hey Tails, you getting this? Knuckles is worried the scary building might fall on us."
Static crackled before Tails' voice came through, slightly distorted but unmistakably amused. "I heard that. And he's not wrong, Sonic. Those old bases weren't built to last—Eggman usually self-destructs them anyway."
"See? Even the kid agrees with me." Knuckles finally stepped through the doorway, his footfalls heavy and deliberate.
"The 'kid' has two Ph.Ds, but sure." Sonic followed, his sneakers making almost no sound against the metal floor. The interior was dark, lit only by the gray afternoon light filtering through cracks in the ceiling. Dust motes drifted like tiny ghosts.
The hallway stretched ahead, lined with dormant computer terminals and overturned supply crates. Wires hung from the ceiling like dead vines. Everything had that particular stillness of a place that had been left in a hurry.
"Sonic, can you describe what you're seeing?" Tails' voice cut through the silence. "I'm trying to map the layout from the old blueprints I found, but Eggman's filed them under at least three different facility codes."
"Uh, lots of metal. Lots of dust. One really judgy poster of Eggman pointing at me that says 'Your Hedgehog Incompetence Fuels My Genius.'" Sonic paused in front of the propaganda poster, its edges curled and faded. "Gotta say, even abandoned, the doc knows how to hold a grudge."
"Stay focused." Knuckles had moved ahead, his fists clenched and ready. His treasure-hunting instincts made him naturally cautious in unfamiliar spaces. "We're looking for any intel on his current operations. If he left this place, there's a reason."
"Maybe he finally got tired of the commute." Sonic jogged to catch up, peering into darkened rooms as they passed. One looked like it had been a cafeteria—chairs scattered, trays still on tables, a mug of something that had long since fossilized. "Seriously though, this place feels wrong. Like everyone just... stopped."
"I'm picking up some weird energy signatures," Tails said, his voice growing more serious. "Faint, but they're not matching any known Eggman tech. Can you find a computer terminal that still has power? I might be able to pull data remotely."
They continued deeper into the facility, the darkness growing thicker. Knuckles pulled out a flashlight—practical as always—and the beam cut through the gloom like a knife. The walls here were cleaner, more maintained. They were getting into the research sector.
"There." Knuckles pointed to a door marked "Laboratory 7-B." It was slightly ajar, a faint blue glow emanating from within.
Sonic pushed it open with one finger, and it swung wide with a prolonged creak that would've made a horror movie director proud. "After you, tough guy."
"I'm not going first just because you're scared."
"I'm not scared. I'm strategically allowing the guy with the punch-through-diamonds fists to take point. Big difference."
Knuckles snorted but entered first anyway. The laboratory was in better condition than the rest of the facility—pristine, even. Multiple workstations lined the walls, and in the center stood a massive cylindrical containment unit, its glass surface fogged and dark. The blue glow was coming from a single active terminal near the back.
"Jackpot," Sonic said, moving toward it. The screen displayed lines of text, equations, and what looked like genomic sequencing data scrolling endlessly. "Tails, we got a live one. Patching you in."
"Give me a second..." The sound of rapid typing came through the communicator. "Okay, I'm in. This is... huh."
"'Huh' good or 'huh' bad?" Sonic leaned closer to the screen, though the scientific jargon might as well have been written in ancient Babylonian for all he understood it.
"'Huh' weird. These files are labeled 'Project Eventuality.' Looks like some kind of biological research, but the classification codes are higher than anything I've seen from Eggman before. Like, way higher."
Knuckles had moved to the containment unit, wiping away some of the fog with his glove. He froze. "Sonic."
"Kinda busy here, Knux."
"Sonic." The edge in Knuckles' voice made Sonic's quills stand on end. He turned.
Through the clearing glass, something dark was visible inside the cylinder. Not a robot. Not a creature. Something that looked like it had been both and was now neither—a twisted mass of organic matter fused with mechanical components, all of it covered in a substance that seemed to absorb the light around it. Black tendrils, dormant and coiled, reminded Sonic of oil mixed with rot.
"Tails, buddy, please tell me that thing is super dead."
"I'm reading the notes now. They're... fragmented. Dated from about eight months ago." Tails' voice had lost its usual confidence. "Something about 'accelerated decomposition' and 'self-sustaining decay chain' and—oh. Oh no."
"What? What's 'oh no'?"
"There's a note here. Handwritten. It just says: 'Containment breach, Lab 4. Stop it before it learns. Evacuation Protocol Sigma. —I.R.'"
Sonic and Knuckles exchanged a glance. Ivo Robotnik's initials.
"Tails, what's in Lab 4?"
"I... I don't know. It's not on any of the blueprints. But there's a map here showing it's in Sub-Level 3. And Sonic?" Tails paused. "According to these files, whatever was in there... it's not there anymore."
A sound echoed from somewhere deep in the facility. Distant. Wet. Like something dragging itself across metal.
Sonic's smirk faltered for just a moment. "You know what? I'm starting to think Eggman's 'crazy scientist' routine is less routine and more actually-crazy-scientist."
"We need to find Lab 4," Knuckles said, already moving toward the door. "If something got loose—"
"Then it's been loose for eight months, and nobody's seen hide nor hair of it. It's probably just..." Sonic gestured vaguely at the terminal, at the notes, at the thing in the cylinder. "Maniac jargon, right? Eggman gets dramatic. He probably just moved operations and wanted to freak out anyone who came snooping."
But even as he said it, Sonic found himself looking back at the containment unit. At the dark mass inside that seemed, just for a moment, to have moved.
"Let's check out Lab 4," he said quietly. "Just to be sure."
The stairwell to Sub-Level 3 was narrow, the metal steps slick with condensation. Their footsteps echoed in the confined space, each clang seeming to announce their presence to whatever might be waiting below. The blue glow from Knuckles' flashlight beam danced across walls covered in peeling warning labels: AUTHORIZED PERSONNEL ONLY. BIOHAZARD PROTOCOLS IN EFFECT. PROTECTIVE EQUIPMENT REQUIRED.
"Real inviting," Sonic muttered, his usual bravado sounding thin even to his own ears.
"You wanted to check it out," Knuckles reminded him.
"Yeah, well, peer pressure's a real problem. Tails made me do it."
"I can still hear you," Tails' voice crackled through the communicator, slightly distorted by the interference of the thick metal walls. "And for the record, this was your idea."
They reached the bottom of the stairwell. The door ahead was heavy, reinforced, with a faded number 3 stenciled across it. Knuckles tested the handle. Locked.
"Step back," he said.
Sonic obliged, and Knuckles drove his fist into the door mechanism. The metal shrieked and buckled, and the door swung inward with a groan that sounded almost pained.
The hallway beyond was different from the upper levels. Cleaner. Colder. The emergency lighting still functioned down here, casting everything in a sickly red glow. More concerning was the smell—antiseptic mixed with something organic and wrong, like meat left too long in the sun.
"Okay, that's not ominous at all," Sonic said, covering his nose.
They moved forward, passing more laboratories, all of them dark and apparently empty. Lab 4-A. Lab 4-B. The numbers climbed until finally, at the end of the corridor, they found it: Lab 4.
The door was different from the others. Thicker. Covered in more warning labels. And across it, someone had spray-painted in large, frantic letters: DON'T.
"Well," Sonic said, staring at the message. "That's... helpful."
"The door's sealed from the outside," Knuckles observed, running his hand along the frame. Multiple locks had been engaged, and what looked like a welding job had been attempted around the edges. "Someone really didn't want whatever was in there getting out."
"Past tense being the operative word." Sonic pointed to the bottom corner of the door, where the metal had been torn—not cut, not blown open, but torn—leaving a gap just large enough for something to have squeezed through.
"Tails, we found Lab 4. And uh... it's been compromised."
"Can you get inside? I need to know what was in there."
Sonic and Knuckles exchanged another look. Knuckles shrugged. "We came this far."
"Alright, but you're going first this time."
"Why me?"
"Because you're braver, stronger, and more handsome. Also because I'm faster and can therefore retreat more tactically."
"Coward."
"Tactician."
Knuckles grabbed the edge of the torn metal and pulled. The door resisted for a moment, then gave way with a screech that set Sonic's teeth on edge. The gap widened, large enough for them to slip through.
"After you, oh brave and handsome echidna," Sonic said with an exaggerated bow.
Knuckles snorted but went first, squeezing through the opening. Sonic followed, and they found themselves in what had once been a pristine research laboratory. Now it looked like a disaster site. Equipment was overturned, glass littered the floor, and the walls bore long scratch marks that seemed almost deliberate in their pattern.
"What happened here?" Knuckles murmured, his flashlight sweeping across the destruction.
"Nothing good." Sonic moved toward a desk that had somehow remained upright. Papers were scattered across it, covered in Eggman's manic handwriting. He picked one up, squinting at the text. "Okay, we got more science-speak here. 'Exponential growth rate'...'consumption of organic and inorganic matter'...'demonstrates problem-solving behavior'... Yeesh, this is like reading a really depressing cookbook."
"Sonic, look at this." Knuckles was standing near what looked like another containment unit, but this one was shattered from the inside. Glass crunched under his boots. "Whatever was in here—"
The sound of skittering cut him off. Fast. Coming from the shadows in the corner of the room.
Both of them tensed. Knuckles raised his fists. Sonic shifted into a ready stance.
The skittering grew louder. Closer.
"On three," Knuckles whispered. "One... two—"
Something small and dark burst from the shadows, charging directly at them with a high-pitched squeal.
"SWEET CHEESE AND CRACKERS!" Sonic yelped, jumping a solid three feet backward and nearly tripping over his own feet.
A rat—just a normal, very angry rat—scurried between them and disappeared through the torn doorway, its tail whipping behind it like a tiny furious flag.
There was a beat of silence.
"Did you just scream?" Knuckles asked, his voice carefully neutral.
"That was a tactical alarm. To warn you. Of the threat."
"It was a rat."
"A fast rat. Could've been rabid. You don't know." Sonic straightened his quills, trying to recover some dignity. "Anyway, as I was about to say before we were so rudely interrupted by rodent-kind, I think we've seen enough."
"There's nothing here," Knuckles admitted, looking around the destroyed lab. "Whatever was in that container is long gone."
"Exactly. So I'm calling it. Tactical retreat time." Sonic was already moving toward the door. "We've explored, we've conquered, we've been terrified by wildlife. Mission accomplished."
"You mean you're spooked."
"I mean I'm smart enough to know when we're wasting time in a creepy abandoned lab that smells like a hospital's dumpster." Sonic squeezed back through the torn doorway. "Come on, let's blow this popsicle stand."
Knuckles took one last look around the lab, his instincts telling him something was off, but with nothing concrete to point to, he followed Sonic out.
They made their way back through Sub-Level 3, up the stairs, and through the facility much faster than they'd entered. The sense of wrongness seemed to follow them, but nothing else did. No more sounds. No more signs of whatever had been contained in Lab 4.
When they finally emerged into the late afternoon sunlight, Sonic took a deep breath of fresh air like a man surfacing from deep water.
"Tails, we're out. Lab 4 was trashed, but empty. Whatever was in there is gone—probably died or wandered off months ago."
"Did you find anything useful in the notes?" Tails asked.
Sonic patted his quills and realized he'd left the papers behind in his graceful retreat from the rat. "Uh... negative. Just more of Eggman's usual mad scientist rambling. Nothing we need to worry about."
"Alright. I'm marking the facility as explored and empty in our database. Good work, guys."
"Another day, another creepy base," Sonic said, his trademark grin returning now that they were in open air. "Race you back, Knux?"
"You'll just cheat."
"It's not cheating, it's being aerodynamically gifted." Sonic was already taking off, his blue blur disappearing down the trail.
Knuckles followed at his own pace, glancing back once at the facility. In the fading sunlight, it looked even more lifeless than before. Whatever had happened here was over. Done. Ancient history.
He turned and headed after Sonic, leaving the abandoned base to its silence.
***
The smell of chili dogs—homemade, not the gas station kind Sonic usually inhaled—filled Tails' workshop. Amy had taken over the small kitchen area with the efficiency of a field general, her red dress traded for a practical apron that read "Kiss the Cook (Or Face the Hammer)."
"Knuckles, can you pass me the paprika?" she called over her shoulder, stirring a large pot with one hand while checking her recipe tablet with the other.
Knuckles, who had been standing awkwardly near the counter like he wasn't sure what to do with himself indoors, grabbed the spice jar and handed it over. "Why do you make these things so complicated? Food is food."
"Food is art," Amy corrected, adding a precise amount to the pot. "And after the day you boys had poking around that creepy facility, you deserve something better than Sonic's usual diet of questionable meat tubes and whatever's not moldy."
"Hey, I resent that remark," Sonic called from where he was sprawled across the couch, one leg dangling over the armrest. He was flipping through a comic book, though he'd read this issue at least a dozen times. "And for your information, I checked the expiration date last week. Only mostly expired."
"You're disgusting," Amy said, but she was smiling.
Tails sat at his workbench, a holographic display floating in front of him showing schematics of a new Miles Electric prototype. His twin tails swished absently as he worked, occasionally reaching for tools without looking. "We should have enough for everyone. Amy, you made extra, right?"
"Of course! I was thinking we could invite Rouge and Shadow over. We haven't all gotten together in ages, and—"
"They're not available," Tails said, not looking up from his work. "Those two have been off on GUN missions for months now. Total communications blackout. Shadow's on some kind of deep cover assignment, and Rouge is... well, Rouge. Doing Rouge things for the government."
Sonic glanced over the top of his comic. "Months? Seriously? What's GUN got them doing, infiltrating the moon?"
"Classified, probably." Tails finally looked up, pushing his goggles onto his forehead. "I tried reaching out to Rouge last week just to say hi, and her number's been disconnected. They must be really serious about the no-contact thing this time."
"Shadow's probably loving it," Sonic said, going back to his comic. "Mister 'I Work Alone' gets to brood on a mission without anyone asking him how he's feeling. It's like his birthday and Christmas combined."
"Be nice," Amy chided, though she couldn't quite hide her own smile. "Shadow's... well, he's Shadow. But he's reliable when it counts."
"Oh, I know. Guy's saved the world almost as many times as I have." Sonic turned a page. "Still doesn't mean he's not a drama king about it."
Knuckles had migrated to the window, looking out at the darkening sky. "It's been quiet lately. Too quiet."
"You sound like a character from one of Sonic's bad action movies," Tails teased.
"They're not bad, they're classic," Sonic protested. "There's a difference."
"There really isn't."
Amy tasted the chili, nodded in satisfaction, and turned down the heat. "Knuckles has a point though. When was the last time we dealt with Eggman? It's been... what, two months?"
"Two and a half," Tails confirmed. "That incident at the chemical plant. He was trying to mutate animals again with some new roboticizer prototype."
Sonic snorted, finally setting down the comic. "Yeah, and I kicked his shiny metal butt so hard his mustache probably still hurts. Guy's probably sitting in whatever new evil lair he's set up, nursing his ego and building an even more ridiculous robot to throw at us."
"The last one was called the Egg Destructor Supreme Deluxe Edition Mark VII," Tails recalled. "He's really running out of names."
"He ran out of good names somewhere around Egg Viper," Sonic said. "Everything after that has just been him throwing words at a wall and seeing what sticks."
Amy brought bowls to the small dining table, gesturing for everyone to sit. "Maybe he's finally taking a vacation. Even evil geniuses need time off."
"Eggman doesn't do vacations. He does 'strategic retreats' and 'planning phases.'" Sonic dropped onto a chair, eyeing the chili with obvious approval. "But hey, I'm not complaining. Let the doc have his sabbatical. Gives me time to catch up on my napping."
"You nap every day," Knuckles pointed out, taking his own seat.
"Exactly. I'm behind on my napping. Do you know how exhausting it is being this fast and this good-looking? I need at least twelve hours of sleep to maintain this level of awesome."
"You need therapy," Tails muttered, but he was grinning as he joined them at the table.
They ate in comfortable companionship. The conversation drifted from topic to topic—Amy's latest attempt to get Cream to try martial arts training ("She's too sweet, Amy. You're going to give her bunny PTSD"), Knuckles' ongoing paranoia about leaving the Master Emerald unguarded for too long ("I have a security system now. Tails installed it." "You mean the thing that texts you every time a bird lands near it?" "...It's very thorough."), and Tails' newest invention that would supposedly let Sonic run on water more efficiently ("I can already do that." "You can barely do that. You sink every third step.").
Sonic leaned back in his chair, balancing it on two legs. "You know what? This is nice. No robots trying to kill us, no ancient gods waking up angry, no time paradoxes or alternate dimensions. Just us, some good food, and absolutely nothing trying to end the world."
"Don't jinx it," Amy warned, pointing her spoon at him.
"Please. What's the worst that could happen?"
Knuckles and Tails exchanged a look.
"Why did you say that?" Knuckles asked flatly.
"Say what?"
"'What's the worst that could happen.' You never say that. That's like rule one of hero work."
"Oh, come on." Sonic let his chair drop back to all four legs with a thump, laughing. "You guys are getting paranoid in your old age. Next you'll be telling me stepping on cracks actually breaks someone's back."
"It's not about superstition," Amy said, though she was smiling despite herself. "It's about... I don't know, tempting fate?"
"Fate can get in line behind everyone else who wants a piece of me." Sonic grabbed another chili dog from the serving plate. "Besides, we just spent the afternoon in a creepy abandoned lab with nothing but dust and one very aggressive rat. If that's the universe's idea of excitement, I think we're in for a pretty boring month."
Tails pushed his empty bowl away and stretched, his twin tails curling contentedly. "Maybe boring would be nice for once. I've got three projects I've been putting off because we keep having to save the world."
"What kind of projects?" Amy asked, genuinely curious.
"Well, there's the water propulsion system for Sonic—"
"Which I don't need—"
"—which you absolutely need because you nearly drowned last month—"
"I was tactically submerging—"
"—and I'm working on a new scanner that can detect Chaos energy signatures from further away. Could help us track the Emeralds if they ever get scattered again." Tails' eyes lit up the way they always did when he talked about his inventions. "Oh, and I'm trying to build a universal translator that works on animal languages, not just—"
"Eggman's robots, yeah, we know," Sonic finished, grinning. "You've been talking about that one for two years, bud."
"It's complicated! Do you know how many dialects of Flickie there are?"
"No, and I'm pretty sure I don't want to."
Knuckles stood, carrying his bowl to the sink. "I should get back to Angel Island. The Master Emerald doesn't guard itself."
"You literally just said you have a security system now," Amy pointed out.
"A security system Tails built." Knuckles shot the fox a look. "No offense, but the last three things you've built for me have had... issues."
"The auto-turrets only targeted you because you kept sneaking up on them to test them!"
"They're supposed to recognize me!"
"They did recognize you! As a threat! Because you were acting threatening!"
Sonic laughed, nearly choking on his food. "I still can't believe you got shot by your own security system."
"It was a warning shot," Knuckles muttered.
"It was three warning shots. In a row. While you were running away."
Amy covered her mouth to hide her giggle. "Maybe Tails should add a 'recognize owner' feature."
"That is literally already a feature!" Tails threw his hands up. "I programmed in his biometrics and everything! But apparently someone has trust issues and kept approaching in 'stealth mode' to see if he could fool them!"
"I need to know the system works!"
"It does work! It worked perfectly! You're just mad it worked on you!"
The banter continued for another twenty minutes. Amy told them about her latest attempt to teach self-defense classes in Station Square ("Nobody takes pink seriously until they're on the ground wondering what happened"), and Sonic recounted the time he'd accidentally run through a wedding ceremony at the beach and somehow ended up in half the photos.
Eventually, though, the evening wound down. Knuckles was the first to leave, citing an early morning patrol of Angel Island. Amy left shortly after, reminding them about a charity event next week that they'd all promised to attend ("And by 'promised,' I mean you're all going and I'm not taking no for an answer").
That left just Sonic and Tails in the workshop, the younger fox already cleaning up.
"You don't have to do that now," Sonic said, sprawled back on the couch. "Leave it for tomorrow Tails."
"Tomorrow Tails will thank tonight Tails." He wiped down the counter, then paused, his back to Sonic. "Hey, can I ask you something?"
"Shoot."
"That facility today. Did it... did it bother you at all?"
Sonic cracked one eye open. "The creepy abandoned lab full of ominous warnings and mysterious science projects? Nah. Why would that bother me?"
"I'm serious." Tails turned around, his twin tails still now. "All those notes about containment breaches and evacuation protocols. And something was in that cylinder, Sonic. Something that made Eggman of all people run away."
"Tails, buddy, we've fought a guy who could control time, robots the size of buildings, and literal gods. If it was something actually dangerous, we'd have heard about it by now." Sonic sat up, his tone gentler. "Whatever was in that lab either died or wasn't as scary as Eggman thought it was. The doc has a flair for the dramatic, remember?"
"I know, but..." Tails fidgeted with the dish towel. "What if we missed something? What if we should have looked harder?"
"Then we'll deal with it when it shows up. That's what we do." Sonic stood and walked over, ruffling the fur between Tails' ears. "Hey. We're good at this, remember? We've saved the world more times than I can count, and that's saying something because I can count pretty high."
"You can count to twenty. And you use your fingers."
"See? Pretty high." Sonic's grin was infectious. "Look, if there was something to worry about, we'd know. Trust me. My danger sense is tingling exactly zero percent right now."
Tails managed a small smile. "Your 'danger sense' is just you being reckless until something explodes."
"And it's worked out great so far! That's the important part." Sonic headed for the door, then paused at the threshold. "Get some sleep, bud. And stop worrying so much. The world's not going to end just because we left a creepy lab without writing a full report."
"I know. It's just..." Tails set down the towel. "Sometimes I think you don't take things seriously enough. Like one day we're going to face something that needs us to be more careful, and we won't be ready because we're too used to just running in and punching first."
Sonic was quiet for a moment, his expression unreadable in the doorway's shadow. Then he turned, his trademark smirk back in place but something older flickering in his green eyes.
"You might be right," he admitted. "Maybe someday we'll hit something that needs more than speed and attitude. Maybe someday I'll have to start taking things seriously, planning things out, being all tactical and stuff."
He stepped out into the night, the cool air ruffling his quills.
"But someday ain't today."