I tend to feel Sonic stories ought to have a 'version of reality' explanation attached to them, there's so many variations of canon. This one could fit almost anywhere, although I do tend to mentally default to Fleetway's version of affairs. It's also set relatively recently after Knuckles first meets the others, certainly within the first year.
Knuckles stood on the lower slopes of the Island's central volcano and looked out across the fresh fallen snow. The air was frigid and the glare of the sun on the brightness made him squint as he scanned the view, but on the whole, Knuckles liked snow.
It made his job easier.
When it was coming down – and on the Floating Island it came down in blizzards or not at all – it was all but impassable. Anyone attempting it who didn't want to find themselves up to their neck in a drift, or blundering into one of the traps, would need to know the Island as well as Knuckles himself.
No one did.
Then when it had settled, cold and still and pristine, sound carried for miles. Any intruder might as well wave a flag and blow a trumpet to announce their presence as attempt to cross the glittering landscape.
Knuckles groaned. Sonic. Flags and trumpets had nothing on the attention-getting abilities of one blue hedgehog tearing through the snow. He wasn't alone either. The miniature snow-flurry trailing along behind him, could only be the fox cub, the downdraught from his eponymous, spinning tails whisking up a whirling dervish of snow in his wake.
Reluctantly, Knuckles tromped down from the foothills to meet them. He'd been rather enjoying the view until then. The clearly untouched snow had been quite satisfying, a visual reassurance that he was alone and the Island was free of interlopers.
Of course it was frequently Sonic who shattered that particular illusion anyway.
"Well?" Knuckles asked, as the hedgehog ploughed to a halt, throwing up a wave of snow that showered all three of them. "What do you what?"
"Way to say hello, Knux!" Sonic grinned, as irrepressible as usual in the face of this complete lack of welcome. "Just thought we'd come up and, y'know, say hi."
"Did you," Knuckles said, his tone making it a flat statement, instead of a question. He frowned as a thought struck him. "How did you? The snow's three foot deep everywhere flat enough to land."
"I put skis on the Tornado!" Tails beamed.
"Did you." Knuckles repeated, resigned. "So what do you want?" He asked again as Sonic opened his mouth. "And don't give me any of that 'you just though you'd pop in' either. You never come up here without a reason."
Even if it's just to irritate me, he added, silently.
Sonic tipped his head on one side, paused as though considering his answer then said, "Oh well, if you must know, Amy was worried you might be snowed in and need some help." He waved a hand vaguely. "Or supplies. Or something."
This was so far from any reason which Knuckles might have guessed that he was momentarily lost for an answer.
"Worried?" He found himself parroting.
With the exception of Sonic's uninvited visits, he'd had only fleeting contact with most of those on the surface, and that only when an external threat had thrown them together. The thought that anyone would even consider what he did with himself outside of those occasions, much less worry about it, was unexpected. He wasn't quite sure how he felt about it. Should he be flattered? He actually felt rather indignant.
"What does she think I did last winter or the one before that, before I knew any of you even existed?" He'd blurted it out before he belatedly realised that gratitude probably ought to have been somewhere in the emotional mix.
Sonic only shrugged, clearly he did not consider Amy's logic, or lack thereof to be his problem.
"So you're alright for food and stuff? Woolly hats? Whatever?"
Knuckles rolled his eyes. "Do you know how long I've been up here, looking after myself?"
"No?" Sonic said.
"How long?" added Tails, curiously.
Knuckles was brought up short again. It had been a rhetorical question and he didn't feel he could reasonably turn round and answer that actually he wasn't certain either.
"I-- Long enough!" he snapped. Sonic was smirking and Knuckles suspected he knew exactly why.
"I have plenty of supplies," Knuckles said firmly, in the vain hope that Sonic would leave faster if he failed to provoke him. "I have shelter. I am absolutely fine here. On my own."
Good!" Sonic said brightly. "'Cause really that was just a handy excuse for me 'n Tails to get away to enjoy the snow. Everyone back home is digging out paths and booorrriinnnggg stuff like that and we'd only have got roped in if we'd stayed."
"So all that about checking on me was a lie?" Knuckles was angry now and felt rather foolish.
"Na she really did say that. There's some stuff in the 'plane if you needed it." Sonic shrugged, "I was sure you'd be fine though. I just thought it'd be a laugh to come up here – it's kind of pretty in the snow." He looked around then lightening fast had ducked to the ground and grabbed a handful of snow, "And perfect sort of snow for this!"
Knuckles stumbled backwards, spluttering, as he was hit square in the face by a double handful of powered snow.
Sonic was laughing so much he was staggering. "You should see your face, Knux! Haven't you ever had a snowball fight before?"
Knuckles scowled and raised both fists, "If it's a fight you're looking for, hedgehog..."
He got no further as a second snowball hit him smack in the side of the head. He spun round to see Tails already in retreat, though he paused long enough to pitch two more at Sonic. The hedgehog dodged one, but took he other on the back of the neck with a squeal. And that was odd, Knuckles realised, as he watched Sonic fling another double handful at the fox, because he should have been fast enough to dodge both. It was a game then, and one, for once which Sonic wasn't 100% intent on winning.
Almost hesitantly, Knuckles scooped up a large handful of snow and squeezed it between his paws. Whether he realised it or not, Sonic was right in saying Knuckles had never thrown a snowball but he'd knocked fruit from trees with pebbles and attacking bots from the sky, and Sonic was running now, but in a straight line and in a second and a half he'd be... about... there!
The hedgehog's eyes crossed most satisfactorily as the missile hit home and he reeled to a halt. He looked at Knuckles, then down at the still intact snowball, which had been compressed to an almost solid lump of ice.
Sonic rubbed his head. "Good shot," he said. "We may need to work on some of the more basic ideas, but good shot..."
Tails almost fell out of the sky laughing.
"You started it, Sonic!" he giggled. "You started it!"
"Oh yeah? I'll finish it too! Come back here, squirt!"
The fox squeaked and thrashed his tails for altitude. Sonic dashed after him, but was felled by a carefully aimed shot to the ankles.
"Nice one!" Tails yelled to Knuckles, then ducked as a second snowball whizzed past his left ear. "Hey!"
Knuckles' eyes shone with rare amusement. "Don't think I'm forgotten where the second snowball came from – I owe you one too."
Half an hour later, panting steam into the chilly air, and with pelts dripping with snowmelt, Sonic and Tails followed an equally bedraggled Knuckles into an almost invisible cleft in the hillside which opened into a dry, roomy cave. A recently used fireplace was tucked in the most sheltered corner along with several crates and one stool. Knuckles fished some thing out of the nearest crate and gestured.
"You may as well sit on the boxes. I don't exactly have guest quarters."
He quickly lit a fire and they were soon drying out and passing around a hot drink – Knuckles one stool was matched by his one mug. Nevertheless the tea was warming and the general atmosphere cosy and comfortable, especially when Knuckles passed round some sticky dried fruits.
"You really are well supplied up here aren't you?" Sonic looked around, his mouth full.
"Not just here," Knuckles said, and a trace of pride crept into his voice. "All over the Island. I always have somewhere to go if I need to."
"Somehow I always pictured you kipped down under the Master Emerald or something."
Knuckles shrugged. "Sometimes, but I would know if anyone was there, and it is unwise to become too predictable."
Sonic fingered the bruise forming on his forehead.
"I'll have to remember that," he grinned, wryly.