Hi there and welcome to "Advent Of Equinox", co-written with the wonderful SKYBLAZE (go check out her sonic fics, link on my profile) and my first collab ever! As always, care will be taken that it'll remain understandable even if you haven't played the recent games and can enjoy it. Please have fun! :D

Advent of Equinox

by Skyblaze & Taranea

Chapter 1: Shadow on the Sun

The air was dusty with the smell of late summer. The sun was high overhead bathing the forest and the broad, grassy plain with intense warmth.

A breeze swept across the landscape, the weeds bowing before the power of the wind as it got stronger, followed moments later by the whip-crack sound of a sonic boom as a super-fast blue hedgehog whipped past at somewhere around mach 2.

Sonic smiled as he enjoyed the day. The planet had been peaceful of late, after the disaster with Dark Gaia over a month ago Robotnik had been quiet - no doubt licking his wounds and cooking up a new plan. The megalomaniac scientist had single-handedly upset the balance of Mobius' life force, two beings called Light and Dark Gaia resting within the planet. It had caused Sonic to turn into a sort of wolf-creature as soon as the sun went down, a result stemming from the hero being infected by said Dark Gaia until he defeated him, and now Sonic supposed Eggman would need at least a couple of months to recuperate. And so, the Hero of Mobius had been left with nothing to do except save the occasional feral pet cat from a tree...

Well.

That, and the house-cleaning duties Tails had recently tried to impose on him, which usually meant that it was the blue speedster himself hiding up in trees. But otherwise, this extended vacation worked just fine for him since it left him with lots of time to chill out, hang with his friends and, of course, spend a lot of time just running.

He looked up; grinning as he raced the puffy white clouds sailing across the deep blue sky like one could on a late summer's day – with the exception that if Sonic played this game, he usually won the race. It was a good day. Warm, sunny - perfect for just enjoying life and taking a break from the ever-attendant weirdness that was his life.

Not that 'weird' at times wasn't also really, really cool, mind you.

A chill wind suddenly blew across the plain, making Sonic shiver. He paused, slowing down a little as he felt a strange, almost sick feeling grow in his stomach. Maybe he was pushing himself too hard - it had been a while since lunch and his metabolism needed a lot of fuel to keep running. Chili dog-shaped fuel, if its owner had anything to say about it. He stopped by a large tree, settling himself down under its wide, spreading branches and watched the dappled light dancing on the ground as the sunlight filtered through the leaves.

Light that suddenly seemed a whole lot dimmer than it had before. "Huh?" Sonic blinked, looking up at the sky to see whether it was perhaps a cloud blocking out the sun, whether he should return home in case it started raining, but that thought was dashed when a sudden icy chill gripped him, and let him gasp, dropping to his knees. A sudden wave of darkness swept across the grassy plain, even as his vision was starting to become blackened at the edges.

N-no! This feels exactly like-!

Intolerable pain struck him as all his muscles seemed to cramp at once, the agony of a thousand razors slicing into him as his skin constricted, then burst like an overcooked sausage. His bones shifted, creaking and snapping as they re-aligned themselves into their new shape. The sensation of dozens of tiny needles dancing across his flesh as his fur grew uncontrollably, his jaw hanging open in an expression of unbelievable torture that quickly twisted into a feral snarl as his even, white teeth extended into sharp fangs.

He screamed, but even his scream altered as the terrible transformation went on, becoming the bell-like howl of a wolf. His eyes and muzzle pointed towards the sky and he could see the dark disk that covered the sun in an eclipse.

Finally, it was over and Sonic collapsed onto all fours, panting and shaking with fear and pain. The previously bright, sunny plain was bathed in a silent, unnatural twilight. He looked down at himself, seeing the sharp claws and muscular arms of the wolf.

"No…" he breathed, and the word came out in the deep, bass growl of his night-time self. "Not again."

He looked up again, desperate to see the sun. He panted, green eyes staring at the haloed disk that hung in the sky, begging for it to move, to end the bizarre madness. Praying that this was a dream, a nightmare…

The black blot across the sun moved, uncovering the yellow-orange orb in the sky and once the sunlight began to race across the grassy plain, chasing away the sudden darkness and chill, Sonic felt himself shifting back to normal. He breathed deeply, trying to flow with the transformation as much as possible and not fight it.

When the sun had returned, and everything once again seemed to be as normal as it ever was, Sonic almost relaxed until the sound of a shrill scream of pure agony reached his ears and he whirled around. It had been a shriek of almost unnatural, animalistic pain, but at the same time sounding like no animal he had ever heard.

Quickly, he levered himself to his feet, his ears twitching as he tried to pinpoint the source of the sound. Another tortured yell rang out and Sonic took off after it, forcing his aching, trembling muscles to co-operate. He ran until he found a dip in the gentle rolling grassland.

The screams had stopped now, subsided into a kind of low, desperate moaning of the sort expressed by someone who was still in massive pain despite the immediate source of the agony being gone.

Arriving at the source of the sound, Sonic stopped dead.

In the centre of the low dip cowered the dark figure of Shadow the Hedgehog. He was curled up on himself, though unable to do as he obviously wished and completely roll himself into a ball as hedgehogs in great distress instinctively would. His hands looked strangely distorted, bent into talons that had torn completely through his white gloves; the tips of them plunged into the soft earth.

The grass around him was wet, spattered with a fine spray of dark red blood that dripped silently down from the torn flesh on his back and from the huge, black, bird-like wings that now adorned his shoulders, protruding all the way down along his spine between his quills. He was trembling violently, every spasm sending more small drops of blood splashing down onto the grass, the wings glistening wetly in the returned sunlight. Thin trails of crimson liquid were still running down the otherwise pristine black and white feathers whose angel-like appearance belied the abominable way they had come into being.

"Shadow…!" Sonic gasped in horror.

The black hedgehog snapped his head around, deep red eyes looking blank for a moment before they focused and Shadow recognised who he was looking at.

"S-Sonic? What are you doing here?" he rasped, blinking, before seemingly remembering something and red eyes narrowed instantly, teeth bared. "Don't look at me! Leave me alone!"

Sonic stepped closer, almost startled by the sudden hostility, but managed to suppress it. This was Shadow, after all. The guy wasn't known for his open and welcoming nature, and right now he was hurt and obviously in need of some assistance.

"No way, Shadow. I wanna help you."

Shadow glared at him, "How can you possibly help this!" Sonic's eyes widened as Shadow's voice came out in a strained, almost screechy tone as though he had a bad case of laryngitis. Shadow put a hand to his throat, his ears pinned back to his head in horror, "What's happening to me?" he whispered.

Any thought of laughing at Shadow's predicament immediately vanished from Sonic's mind. He remembered how scared he had been when he had first transformed, it had only been by concentrating on Chip's troubles that he had held his own very real terror in check - but then, focusing on other people's problems did tend to distract you from your own.

"Shadow," Sonic began quietly, "I know what you have to be going through right now and I promise I'll help you however I can."

Shadow glared at him, "How can you possibly know what I'm going through?" The black hedgehog tried to growl, and despite his altered voice forcing him to speak in a whisper the intensity of his frustration still came through, "Just look at me, faker!"

Sonic shrugged, "Seen one transformation, seen them all. Not the first time either of us has taken a different form, is it?"

Shadow stared at him, the hostility in his gaze replaced by a more wary calculation, mixed with a healthy amount of distrust and fear, but some curiosity now as well. Sonic supposed it did help somewhat that he wasn't freaking out about this. Then Sonic's gaze was drawn to something he hadn't noticed before…

"Shadow, where did you get that?" Sonic asked, pointing to an object around Shadow's neck. It was a sort of collar made of a dark metal, with a gem of a deep amber colour hanging from it to rest on Shadow's chest. It reminded Sonic strongly of the turqoise bauble he had acquired during his adventure as the wolf, which now rested on his wrist.

"Huh?" Shadow asked, looking down. He raised his arm to take the object in one claw-like hand, moving it so it sparkled in the sunlight, "I have no idea." He sighed in frustration, "I don't know how I even got here. Last thing I remember was being in Westopolis - asleep."

Sonic raised an eyebrow. "You were sleeping in this late?"

Shadow shrugged, making the feathers on his large wings flutter in a curious way. "I was up late helping Rouge in the club last night."

Restraining himself from making any of the multitude of jokes that popped into his head, (any of which would probably have prompted Shadow to try and rip said head off…) Sonic glanced up at the sky and made a thoughtful humming noise.

"Well, faker, if you do have any idea of how to "help" me," – Shadow pronounced 'help' in a way that it made it very clear that he knew the blue speedster's way of 'helping' people usually involved freak adventures, explosions, abused amusement parks and a ridiculous amount of thumbs-ups, and that he wasn't looking forward to any of it – "Where do you propose to start? I don't really want to stay like this." Shadow very slowly attempted to stand up, checking himself every often so the extra weight on his back didn't make him lose his balance and fall back down again. Which would not have looked very dignified, considering he'd end up on his backside.

"Maybe we should go see Tails? He'll probably know something about that eclipse - and maybe he can even tell us something about that new necklace of yours?"

Shadow considered this for a moment, and then nodded, "So you believe the eclipse is responsible?"

Sonic shook his head, "Nah, but it might have somethin' to do with what's going on. I didn't think we were due an eclipse any time soon. Let's go," he replied, turning around and lightly jogging off, speeding up gradually when he heard the distinctive sounds of Shadow's jet shoes just behind him.

After a few moments, he heard a peculiar stutter in the 'swish-swish' noise of Shadow's shoes, which almost let him turn around to check up on the other, but then the smooth noise resumed again, and Sonic relaxed - until it happened again a scant second later. Sonic glanced behind just in time to see Shadow's feet fly up off the ground, sending him tail-over-muzzle straight into the soft earth, skates up and wings askew.

Sonic braked, jogging back to where Shadow was. The Ultimate Lifeform was gingerly getting back up again, brushing off the dirt and grass where it clung to his fur, quills and feathers with a deeply irritated look on his face.

"What happened, Shads?" Sonic asked, quickly looking the other hedgehog over for injury. A small grin tugged at his features and he couldn't resist adding: "Finally 'stumbling' across the fact that I'm obviously the faster of us two?"

"Drag," Shadow responded tersely, not remotely amused by the comment or the pun.

"Huh?"

Shadow controlled his temper with an obvious effort, "Wind resistance. The wings are creating too much drag; it's knocking me off balance."

"You could try actually flying," Sonic suggested.

Shadow glared, "Are you kidding? I just barely got these things – I have no idea how to actually use them." In fact, I'd probably fly straight into the next goddamn *tree*, he thought, but didn't say aloud. The blue hedgehog was acting way too relaxed about this whole issue and the last thing Shadow wanted was for the other to have another reason to crack some inane joke.

Sonic folded his arms thoughtfully, idly tapping one foot on the ground as he did so. Then a slow smile crossed his face, "I think I've got an idea. Be right back." The blue hedgehog dashed off, leaving Shadow standing there, his frustration slowly mounting until Sonic arrived back less than a minute later carrying a length of soft rope.

Shadow stared incredulously at the cord, then up at Sonic.

"No," he said firmly.

Sonic's grin didn't move, but only became wider until he looked like a particularly spiky Cheshire Cat. (But then again, after everything that had happened today, Shadow wouldn't be at all surprised if the blue hedgehog had turned invisible next. In fact, a part of him wished he would.) "C'mon, Shadow. I can't carry you with those wings in the way and I don't think you wanna try using Chaos Control right now."

Shadow's eyes narrowed dangerously, "I am not a kite."

Sonic shrugged, his irrepressible grin still firmly in place, "It's either this or walking."

Shadow ground his teeth, faced with a choice between a rock and a hard place – or rather, a choice of sacrificing his dignity completely or trying to run and crashing into said rocks. Repeatedly. "Fine," he snapped.

"Heh, knew you'd come 'round." Sonic grinned as he cheerfully tied the rope into a surprisingly secure harness-like arrangement around Shadow's waist and torso, using the opportunity to give the wings a quick, curious brush with his hand as if he himself couldn't believe they were actually real. "Okay, Archangel, open up!" he prompted him as soon as he was done, stepping back to admire his handiwork.

Reluctantly, Shadow spread his wings wide for the first time, his new appendages catching the sunlight, the white feathers scattered here and there seeming almost incandescent under the midday sun while the black feathers and the red-tipped pinion feathers provided an interesting visual counterpoint.

"Ready?" Sonic asked politely as he took hold of the rope. Shadow wasn't quite sure why it still sounded more like a threat to him.

"Just get on with it," the winged hedgehog said through clenched teeth, moving his wings carefully, the feeling of the new muscles moving under his fur strange and curious.

Sonic started to run, pulling Shadow along with him at first, but then the resistance from the wind got stronger and stronger until Shadow rose ponderously into the air where his quills fluttered in the breeze like a wind-sock.

"This is humiliating," he grated, words drenched in enough disdain to drown a small mammal.

Sonic just laughed, "Ah, relax, Shads! Maybe you'll even get to enjoy it! Look, I'm sure this trip to Tails will just fly by – geddit?"

And with the barely-audible sound of Shadow's disgruntled muttering (and very pointed opinions on his sense of humour) in his ears, Sonic set off for the Mystic Ruins and his little brother's workshop, the very first pair of literal kite runners on Mobius on their way.

To be continued…

Heh, you liked? :) This fic will only feature canon relationships between characters, however, there is a SonicxShadow slash version available, hosted on Skyblaze's account somewhere else. (Now, raise your hands who is any way surprised by this...) If any of you would prefer to read that one, just PM us and we'll point you in the right direction :P On here, this will be a pure adventure/comedy story, though. Whatcha think? Please tell me and Skyblaze your thoughts, and if you read, please review! :D