This was originally part of Transitions but on editing it felt like an already long fic was diverging even more into just character waffle ;-) I like it though so tidying it up and present it here. Without the fic that surrounded it, it's left to the reader's imagination what exactly they're keeping watch in case of!
Sonic had actively suggested Tails take the first watch and the fox was a little embarrassed by how proud he was of that. Even it was because Sonic was afraid he'd nod off later. He was less sure what to make of the fact that Knuckles hadn't protested either. The echidna was less tolerant of risk than Sonic but he probably had an atypical notion of what constituted a reasonable level of age versus responsibility.
It had been Sonic's opinion that Knuckles had to go either first or last on the grounds that: "Can't have him thumping someone by mistake if he wakes up grumpy."
Knuckles had muttered something about thumping Sonic there and then if he carried on, but had lain down by the fire with a certain amount of finality, leaving Sonic to shrug and follow suit.
Tails had initially wondered if Sonic was truly as asleep as he looked, but the snores now coming from the untidy sprawl of spines and limbs was too recognisable to be feigned.
Knuckles, it turned out also snored, though not quite with such open mouthed abandon as Sonic.
Tails smiled and built up the fire before following the sparks up into the air to survey the area from above.
Sonic shook off small-hours grogginess as quickly as he did everything else. The night air was fresh and cool and the stars, this far from any habitation, were bright in a cloudless sky, like a million billions rings twinkling temptingly in the distance.
Tails, who'd seemed alert enough when he wakened Sonic, but was yawning by the time Sonic was on his feet, was already apparently sound asleep, tucked into the small hollow Sonic had vacated.
Knuckles was snoring and Sonic grinned and made a mental note to rib him about it in the morning. The snores were muffled only slightly by the fact he was curled tightly into a ball at the outer edge of the firelight. Tense and wary, even in sleep.
Sonic took an idle moment, since there were nothing but idle moments at this hour of the pitch-dark morning, to wonder how much of that was due to being here, so far from his home, and how much was just Knuckles.
It wasn't an answerable question and Sonic got to his feet to take a two-second circuit of their perimeter.
Knuckles went from sound asleep to instant fight or flight (mostly fight) in the length of a heartbeat. The hedgehog was on the opposite side of the fire, smirking at him. Ashes and sparks settling around him in the wake of his movement.
"Well, that's pretty much what I was afraid would happen, yeah," he said. "You always wake up swinging?"
Knuckles glared at him but kept his voice low, aware of the still sleeping shape of Tails handspans away.
"When booted in the ribs by hedgehogs I do."
Sonic scoffed. "It was the tiniest of tiny toe-prods. Don't whine."
Knuckles frowned, the adrenaline of being woken slowly ebbing. Would it be considered a 'whine' to explain to the hedgehog that nothing except dawn had ever woken him to anything less than trouble? Almost certainly.
He moved closer to the fire, recognising the coldest, lowest part of the night.
"Go to sleep, hedgehog."
Sonic shrugged and flopped down where he was. So close to the fire that one restless move would end in singed spines.
Except the hedgehog didn't move an inch. He was out like a candle the moment he hit the ground, for all Knuckles could tell.
He positioned himself with his back to the fire, letting it warm him without impinging more than necessary on his night vision and settled himself in and easy cross-legged position – comfortable enough to wait, not so comfortable he was at risk of dozing. He listened to the sounds of the place, the rhythms and patterns of wind and wildlife, quietly alert to any change and waited for the day.