A/N: I had Mycroft briefly ruminate on a childhood memory in Shot Birds, realized that memory might be fun to write as a story, and then did so. That's, uh... pretty much the extent of my inspirational process, you guys. Also I am super dying of a head cold right now so I don't really know if the quality is shit or not. I guess who cares?

Music rec for this one is Always Gold by Radical Face, mostly just because it's the best-fitting Holmes brothers theme I've yet found.


::

"Qu'est-ce que tu fabriques ?"

Mycroft raised a brow as Sherlock glanced up at him. The boy was sat on the back garden steps in the midst of tying his shoes, and after a brief blink at his sibling went right back to doing so.

"Looking for pirate treasure," he answered. In English, of course; Sherlock rarely deigned to respond to anyone in the correct language whilst staying with their relatives. The habit was an ongoing ploy, as far as Mycroft could tell, to frustrate their French-speaking grandmother out of ever attempting to hold a conversation with him. After a morning spent listening to Grand-mère's endless interrogations over school assignments, career goals, and far-off romantic prospects Mycroft was sorely beginning to wish his childhood self had thought to try the same trick.

"What, in the garden?" Obligingly Mycroft swapped languages as well. Sherlock had finished tying his shoes and was now frowning up at him like he thought perhaps his brother had gone simple.

"No. There's a cave near the beach, I saw it from the road." Even as he spoke he'd hopped off the steps and begun heading for the gate. Mycroft tilted his head slightly – well, then, that... sounded somewhat dangerous? As a responsible older sibling he should probably intervene and insist Sherlock wait until he'd secured some sort of adult supervision before he went off traipsing about in sea caves. With this in mind, and definitely not looking for a convenient excuse to avoid Grand-mère a few minutes longer, Mycroft followed after his brother.

"Sherlock, hang on-"

Sherlock stopped and turned round questioningly. Just then a voice drifted through the garden from the house.

"Mycroft! Où es-tu parti ?"

Both brothers glanced up. Sherlock's eyes darted mischievously towards Mycroft as the latter made an aggrieved face.

"Grand-mère wants you," the boy pointed out, innocent expression at odds with the hint of sing-song mockery in his tone. Mycroft turned an unimpressed glower on the boy. Before he could snipe back, however, footsteps became audible in the hall leading to the back door, and with a sudden bolt of intense aversion to the thought of yet another bout of questioning from his grandmother Mycroft jumped the last step leading off the porch. He took off at a determined pace across the garden and grabbed his little brother's arm as he passed to drag him along. The two of them made it through the gate and behind the fence just barely ahead of the rear house door opening. Grand-mère's confused, irritable grumbling faded as she moved back into the hall to continue searching.

Mycroft breathed a relieved sigh and glanced over his shoulder through the slats of the fence. If he stayed anywhere near the house she'd figure out where he was within a quarter-hour, tops. And he was beginning to run out of plausible excuses to duck out.

As he turned back to face the road he noticed his brother was now frowning quizzically at him.

"I, er..." Mycroft started, rubbing the back of his neck. Where had Sherlock been going? Down to the shore? Might work. She'd certainly never think to look for him there. With a clearing of his throat Mycroft stood a bit straighter. "I'll just... accompany you, then, shall I? Two's the merrier."

Sherlock was dubious. "You hate the beach."

"When did I ever say that?" Mycroft made to start off along the lane, then abruptly realised he didn't actually know how to get down the steep, rocky hill leading to the shore. He glanced back at Sherlock instead; the boy half-rolled his eyes and headed off in the other direction, Mycroft having to hurry a bit to catch up.

"She's just going to lecture you when you get back, you know. She'll be cross."

Mycroft grimaced. God, if only to have a bit of whatever it was that made the family seem to collectively ignore Sherlock in these sorts of situations.

"I really don't understand why she can't natter on at you for a change. It's like she's completely forgotten she has two grandchildren."

Sherlock smirked over his shoulder. "Eh bien, je ne parle pas très bien français, alors..."

"Oh shut up. You're a manipulative little bastard," Mycroft snapped, scowling. He really had convinced Grand-mère he couldn't speak French, the scheming brat.

Sherlock just smiled sweetly before ducking into a space between houses, wherein there appeared to be a path running through a rusted iron trellis. Short trees and low, scrub-like ground cover stretched out to either side, broken occasionally by backs of houses or the odd garden fence.

They wound their way down the side of the hill their grandparents' house stood atop. Sunlight trickled down through the dappled leaves of the trees, birds sang somewhere far off and the sound of waves echoed from below. Mycroft was distinctly unenthusiastic about the steep grade of the trail they were on. Not liking the thought of falling face-first into gravel he elected to take his time picking the safest route amongst the loose rocks and various bits of fallen trees. Sherlock, of course, was merrily bounding rock-to-log-to-rock ahead of him like a mountain goat.

"You're going to crack your skull in two and die and everyone's going to blame me," Mycroft eventually groused as he turned round a bend to find his little brother, who'd again run off ahead, stood atop a large, craggy outcropping waiting for him.

"I'd have to fall first." As if daring gravity itself to challenge his fearlessness Sherlock jumped right off the top of the boulder and landed on the path. Not so much as a stumble for the feat, and he grinned for his success. With Mycroft once more in view behind him he marched off through the trees. "Come on, Myc, you're slow!"

"There's nothing wrong with having a bit of caution, thank you."

Sherlock didn't answer, instead having chosen to rush ahead once more. By the time Mycroft managed to catch up again they'd made it all the way down to the beach. Waves rushed in a steady rhythm over the rocks, lapping at the sand whilst the sun lit everything sparkling with the typical scenic beauty of the Côte d'Azur. Being a rather out-of-the-way locale they found the shore free of tourists – the only other person visible was a man with his dog, far away past the heat-haze and only distinguishable by the canine loudly barking as it dashed into the water.

"You'll have to climb a bit."

Mycroft startled, having not noticed his brother sat a few metres up the side of what looked like an old road abutment beside the end of the path. He flicked his gaze up and frowned as Sherlock lobbed a small pebble at his head. It bounced off his skull harmlessly but the boy still snickered like he'd accomplished something.

"I'm not going up there," Mycroft snapped. It was practically a sheer wall, broken only by a few tiny ledges just big enough for his scrawny eight year old brother to fit on. Sherlock rolled his eyes and, yet again, jumped off to land on the ground. He stumbled this time but quickly righted himself and took off down the beach towards a rocky outcropping near the water.

"That way!" he called merrily, pointing thusward with a stick he'd picked up somewhere along the trail. Mycroft bit out a sigh, considered just turning back – why'd he even come along on this venture, anyway? He never participated in Sherlock's ridiculous shenanigans. But then abruptly he remembered Grand-mère stalking about in search of him back at the house and grimaced. Ugh, no... climbing a few rocks seemed a far less arduous task than spending an entire afternoon alone with her.

Despite the rough, uneven terrain, and multiple slippery patches where the waves rushed through gaps in the stone, Sherlock had somehow managed to bound up to the top of the rock pile in a matter of seconds. Lord, the child really must be part goat. Mycroft, meanwhile, was left to pick his way hesitantly around loose rocks and false handholds as he tried to figure the least hazardous way up.

"You know it's easier if you just sort of run instead of climb," Sherlock chimed in. Probably he thought he was being helpful, but his little demonstration wherein he nimbly skipped down to where his big brother was and hopped back up again within a few seconds was less than inspiring. "You don't have to use your hands so much."

"I might remind you, Brother Mine, that I have significantly more body mass to shift about than you do."

Sherlock laughed. "Did you just call yourself fat?"

"No," Mycroft snapped, colouring a bit. "I... I called you scrawny, you beanpole."

"Oh, right." Sherlock was still snickering, which rather belied his acquiescence. Mycroft just glowered and resolved to ignore his lunatic goat-brother until he'd safely made it to the top of the rock pile. That took perhaps a minute, which he thought rather good for someone who'd been steadfastly avoiding physical exertion for the majority of his fifteen years. Upon reaching the topmost boulder he shakily stood up, mindful of a loose rock under his left foot, and regarded the scene around them. Lapping waves, sunlight playing off the shining patches of moisture and foam dotted over rocks and sand. And ahead of them, true to Sherlock's word, there was indeed a small sea cave extending into the hillside.

Sherlock hopped easily down the other side of the rock jetty and resumed strolling along the beach, letting his stick drag behind him to leave a long furrow in the sand. Mycroft followed the boy's path down the shifting stones much more slowly. Once safe on solid ground he was forced to catch up to his brother by lightly jogging. With a sense of vague embarrassment he found himself a tad winded when he finally came up alongside his sibling.

Sherlock shot him a mischievous smirk. "Did you want to have a rest or something?"

"Shut up," Mycroft snapped. He set his jaw and straightened up. Alright, deep breath, he was fine. He could handle at least as much exercise as an eight year old, for god's sake. Sherlock trailed behind sniggering to himself as Mycroft set a determined pace down the beach.

Finally they reached the cave. As far as Mycroft was concerned it wasn't all that interesting – small channel of sea water lapping in and out the middle, rocks piled haphazardly up the edges with damp sand filling in everything else. The whole thing extended barely ten metres deep. Still, Sherlock's face had lit up in pure glee. And for that, Mycroft supposed... well, it wasn't unpleasant, really, the waves echoing off the cave walls. Perhaps he could count it marginally worth the trip.

"Mycroft, look, look!" Sherlock had already bounded his way halfway down the central channel and was crouched down next to the water. Mycroft grimaced slightly – if anything fell from the ceiling, ugh – but obligingly walked over to his brother. At their feet was a tide pool in which several small fish swam in lazy circles. Sherlock sat stock-still and watched them with rapt fascination. Honestly, between that and the whole bouncing nimbly about over rocks business Mycroft was sorely tempted to wonder if his brother mightn't secretly be a house cat.

"Congratulations," he droned after a silent moment, unimpressed. "You've found some fish."

For no clear reason Sherlock reached out and prodded said unfortunate animals with the end of his stick. The lot of them sped away, which apparently had the effect of rendering them uninteresting, as instead of continuing to observe them the boy hopped to his feet and turned to venture further into the little cave. Mycroft reluctantly followed. Not as if he had much of anything else to do, really.

"Pirates always bury their treasure under some sort of mark," Sherlock said very seriously. "So we've just got to find the one out-of-place thing and then dig there."

Mycroft baulked. "I'm not going to dig. Have you lost your mind?"

"Well then I'll dig, it doesn't matter." Sherlock pouted slightly, but seemed too preoccupied with crouching down to look under a large stone to really be annoyed. "You should look for things up high, since you're taller. Like on the tops of rocks and stuff."

"You do realise we're not actually going to find any treasure." Despite saying this Mycroft did deign to wander over to a large-ish outcropping of wave-slicked rocks and glanced over the top of them. Nothing interesting.

Sherlock paused for a beat or two, having been upturning a flattish rock, and shot Mycroft an odd sort of look. Not quite upset, nor sad, or annoyed, but some blending of the three. Evidently pirate treasure was some sort of real point of emotional attachment for him. Mycroft met his gaze with a bland stare.

Sherlock fiddled with his stick a bit, then turned away to upend a different rock.

"If you always just assume there's nothing to see then you'll never see anything, you know," he said over his shoulder. Mycroft scoffed. Oh, what was that supposed to be? Some sort of primary-school-aged philosophising?

"Yes, but if I just assume there's nothing in situations where logically there wouldn't be, then I'll have saved a lot of wasted time and effort looking for things that don't exist. It's called resource management."

"But what if they do exist?" Sherlock seemed oddly plaintive about this. "You can't know anything's for sure until you observe it. Assumptions aren't always right." He'd gotten his rock turned all the way on its side and let it tip over backwards so he could inspect the sand underneath it. Mycroft just rolled his eyes.

"Mine are," he quipped blandly. Sherlock frowned back at him with yet another odd look, but Mycroft ignored it. "What do you even want treasure for, anyway?" he continued on, "We've six-figure trust funds. A few thousand pounds in pirate gold isn't going to amount to anything."

Once again he moved off to inspect the tops of a few nearby rocks, seeing no reason to refuse something so trivial as looking for non-existent smuggler's marks. And, once again, there was nothing more interesting to look at up there than a few bits of seaweed.

Behind him Sherlock had abruptly stopped what he was doing. By his body language it was clear the question of their family's wealth somehow hadn't occurred to him. Mycroft huffed an exasperated scoff. All this obsessive fixation on treasure and the idiot hadn't even realised he was already rich, why was that not the least bit surprising.

"I, er..." Sherlock hesitated, thinking carefully. A beat later he went back to inspecting sand as if having made a final decision. "I'll just give the gold to someone else. It'll still be worth looking for."

Mycroft scoffed. "Who would you give it to? You don't know anyone."

"Well someday I'll have friends and everything, won't I? I'll give it to one of them."

"For a boy who's managed to drive off three separate tutors and a nanny in the space of a year I'd say you're being rather optimistic about your social prospects."

Sherlock frowned up at him. "I can make friends."

"How would you know?" Mycroft rolled his eyes again and ambled off further towards the back of the cave, still idly in search of anything 'out of place'. Sherlock abandoned his third overturned rock and got up to follow him.

"Because you're my friend." He pushed past Mycroft's legs to hop a few steps up a large stone-and-driftwood formation. "And having one friend obviously means it's possible to find more."

Mycroft slowed to a stop and stared at his brother. For some reason he was finding himself strangely at a loss for what to say to that. Sherlock didn't seem to take any notice, of course. He'd scrambled up the apex of a craggy boulder and was busy prodding at some sort of disgusting anemone-looking creature with his stick.

A few silent moments passed between them. Eventually, perhaps on instinct, Mycroft stepped forward and plucked his little brother up off the wave-slicked outcropping he'd shifted onto. Sherlock had gotten a bit too big to be carried these days, but he was still plenty light enough for a quick relocation to the much safer sand-coated rocks a metre or so to the side.

"Hey!" the boy exclaimed, indignant over being moved. Mycroft didn't respond. Instead he turned a bit to look out to the sun, sky, and sparkling ocean visible through the mouth of the cave. He huffed a small sigh to himself and glanced back to his brother.

"What do you say to walking back to town and finding an ice cream shop?"

Sherlock lit up at the suggestion, but then almost immediately narrowed his eyes in suspicion. "Aren't you supposed to be on a diet?"

Mycroft sputtered – of all the, he was trying to be nice, for god's- "A single cup of ice cream isn't going to affect my weight," he snapped. Sherlock looked extremely dubious, but began to climb down off the rocks regardless. Mycroft self-consciously straightened his shirt – was doing perfectly well on his waistline, thank you.

As he landed on the sand Sherlock frowned and looked back into the shadows. "What about the treasure?"

"We'll come and look again later."

The boy paused at the mouth of the cave, just behind his brother, who was already out on the beach. His expression was decidedly mistrustful.

"Promise...?"

Mycroft rolled his eyes. What a juvenile question, honestly. As if he'd ever enter into a verbal contract with an eight year old.

"I don't make promises."

But, then, he glanced back to find Sherlock's face had shifted into a look that seemed somehow... let down. Though he shouldn't have been, really. It wasn't like he didn't know his brother's opinion towards childish things like pacts and promises – entirely out of line with personal ethos, led to extraneous obligations. And Mycroft was hardly about to set a precedent of making exceptions in behaviour for his baby brother, was he? Who knew where inconsistency like that might lead.

And yet... Sherlock still looked upset. And all it would take to appease him was a simple, silly word. Nothing egregious.

After a few seconds Mycroft huffed a sigh.

"... I promise."