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turnupswritessometimes · 1 year ago

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Sherliam Oneshot - Lessons in Anatomy

Summary: John murmured, "You don't believe in mermaids?" Sherlock snorted. "Do you? Truly?" "I think, on an expedition to see new species, we shouldn't be surprised to find new species." It was actually wise, even if it was teasing. Sherlock bit the inside of his cheek, bumping his shoulder against John's. "Don't expect me to sew a monkey onto a fish to indulge you."

***

Sherlock, a sailor on an expedition to the Galapagos Islands, gets shipwrecked - and saved, by a mermaid. 'Anatomy lessons' ensue.

AO3 Link: https://archiveofourown.org/works/52038016

Fic under the cut:

Sherlock stood at the rail of the ship, staring at the waves. They lapped against the hull in a steady, insistent rhythm. There was just enough of a breeze to push his hair back from his face; it had been tied back with a thoroughly salt-encrusted rope. His own tie had been lost the first day.

He loved sea voyages. For the first day. The change of scenery; the ocean; the crew and the tales they told. But then the next day was more of the same. Then more of the same. Open sea was, for the most part, not interesting to watch.

He felt like a lion trapped in a cage at the circus. He'd happily leap through fire to be away from the monotony.

And it was even worse because he was so curious about what lay at the end of this voyage. Because they were headed to the Galapagos. This was an Exploration, and they were growing shorter and shorter in supply now the maps were mostly filled out. They would find all manner of strange creatures; the likes had only been recorded in Darwin's journals. Maybe a new species. Certainly there would be something interesting to take back to London.

But ships moved slower than they did in journals, and Sherlock was growing all the more restless. He’d tried to help with the ropes, and only succeeded in getting red burns against his palm. The only help he was to the crew was a violin performance in the evenings, and he was beginning to run out of songs.

"The crew say there's whales, in this area." That was John, at his side. At least he had John Watson, to while away the hours with.

"What a shame we have no hunting supplies." Because that, at least, would be exciting.

John raised his eyebrows. "I thought you didn't much care for hunting. A coward’s sport, you said."

"That's true. There’s no point in killing something just for exciting.” He sighed. "I shall have to content myself with a few grey backs, bobbing in the grey sea."

Though the sea wasn't grey here, not like England. It was picture book cerulean, the sky just a few shades lighter.

"Well, whales have blowholes," John said, seriously. "It will no doubt spray me in the face. That'll give you a good laugh."

Sherlock grinned, just at the thought.

"There ain't just whales, in these waters." One of the crew came behind them, swabbing at the deck as though it were a particularly pesky fly. "There's all manner o' strange creature."

"Oh, aye." Sherlock couldn't wipe the smile away completely. "Mermaids, even?"

"Oh, mermaids and all." The crew member's eyes grew wide, and earnest. "I seen 'em. Clear as day, fluttering through the water like butterflies."

"Well, we'll be sure to keep a weathered eye out."

The sarcasm flew over the man's head. "Just see you do, sir. Just see you do."

The two of them turned back to the ocean view, listening as the man continued his vigorous swabbing. When he was far enough away, John murmured, "You don't believe in mermaids?"

Sherlock snorted. "Do you? Truly?"

"I think, on an expedition to see new species, we shouldn't be surprised to find new species."

It was actually wise, even if it was teasing. Sherlock bit the inside of his cheek, bumping his shoulder against John's. "Don't expect me to sew a monkey onto a fish to indulge you."

John nudged him back. That was the moment the first spot of rain came down. Sherlock looked to the sky. That beautiful blue was suddenly filling with grey clouds.

"You two'd better head inside," the captain called. "Storm's coming, and it'll be a big one."

Even as he finished speaking, the rain became to come down in earnest. Not like English rain; this came down in fat, warm droplets and made the air more humid than ever. It was that humidity that signalled there was a storm on its way.

They complied. Headed back to their cabin and listened to the waves crashing against the hull. To the rain clattering against the porthole. To the deck hands shouting above them.

Thunder came. A rolling thunder that seemed angrier and more foreboding than back in England.

"I say." John steadied himself against the wall. "Do you think they're alright?"

The boat lurched sickeningly to one side. Sherlock slipped, only just catching himself against the wooden wall. It lurched to the other side. The rain spattered against the porthole so heavily that it seemed in danger of cracking.

“No,” Sherlock said, though he couldn’t tell if John heard him, over the roar of the storm. He felt his way to the door, fumbling to get it open against the roaring wind. Every step up to the deck felt like a fight. But eventually he stepped out onto the deck to see chaos. The boards were as slippery as ice, the ropes caught in the wind, lashing like whips, men fumbling to get everything under control.

Sherlock was soaked through in a matter of moments. Lightning flashed in the dark sky.

He grabbed the nearest deckhand by the arm. Yelled, “What can I do?”

“The ropes!” The man replied. “The sails!”

So Sherlock fought his way across the boards. His boots slipped; he crashed to one knee. Ended up crawling to the masts and fighting to grab hold of one of the lashing ropes. It kicked like a snake. He fumbled to copy the sailors around him, his fingers slipping over the rungs of the rope, rain pelting at his back.

The wind howled, battering his cheeks. He gritted his teeth, tugging the rope to knot it.

The cries sounded the same as all the rest. He looked up too late. But the mast was swinging, with a terrifying speed, towards him. Lightning illuminated it for a moment, and in that moment, Sherlock realised that he wasn’t going to get out of the way in time.

The mast hit him in the next moment. Right in his chest. It knocked the breath from his lungs; reverberated through every part of his body. The deck fell away. There was only the wind and the rain; he was in the air.

Then there was rain all around him. No, not rain. The ocean. Salty ocean water that enveloped him whole. Everything was black, and dark and he’d thought the ocean here would be warm, but it was freezing, now.

It was freezing, and he hadn’t had time to take a breath. His lungs screamed, banging against his ribs. His limbs were heavy – too cold and too heavy from the water around him..

And shit, Sherlock thought, shit this was how he was going to die. He wanted to be angry about it, but even that seemed like a huge effort.

There was something in the water with him. It brushed his limbs, and his back.

Then he lost all of his senses.

Sherlock returned to the world with the same sickening thud that had sent him out of it. He lurched upwards; coughing up seawater. It burnt his throat. His hair hung in his face. Everything seemed terribly bright, and terribly hot.

He left a puddle of seawater on the ground. The ground. He blinked, his eyes aching, as it came into focus. There was sand underneath his fingers. But his arms felt like jelly; he couldn’t push himself up.

“That was not as elegant as I thought it would be.”

A voice cut through the roaring of blood in his ears. Sherlock fought to catch his breath, blinking hard. It wasn’t particularly light, after all. It was easier to roll onto his back. The sky was beautiful. Dusky mauve and indigo and a hint of rose in the clouds. Dawn, then.

“You saved me.” Sherlock’s voice was hoarse.

“Perhaps it’s because you are not a maiden.” Fingers brushed dark strands from his face. And a face came into view. The long, blonde hair framing it were as bright as the sun. It hung over his pale shoulders, framing an elfin face. High cheekbones, cupid’s bow mouth. “Or because I am not a maiden.”

Sherlock didn’t have the strength to sit up. His clothes hung, soddenly, to him. He stared up at his saviour. “You’re as pretty as one.”

He hadn’t meant to say that. He’d meant to ask who on earth this was, and how he was still alive.

His saviour smiled, just as elfishly, and it made his eyes glitter. They were a rich, shining red, like conkers.

“Thank you.” The hand was still on his cheek, a thumb trailing down the side, to the corner of his mouth. It pressed there. “You’re rather nice, as well.”

His heart pounded. He managed to raise his own hand, to catch his saviour’s wrist. “What wasn’t as elegant as you thought?” “Saving you.” The boy’s head tilted to the side, causing his blonde hair to ripple. “I thought you’d wake more elegantly.”

“How could you save me?”

“Do you remember? You fell overboard.”

“But I’d remember you on the crew,” Sherlock murmured. He was noticing more; that his saviour wore no shirt. He could see inches upon inches of creamy, pale skin. Could just see a pink nipple, between the strands of hair. His body was just as beautiful; just as elegant; as his face.

“I am not part of your crew, sailor.” The hand moved again, just over his bottom lip – his mouth fell open – to his chin.

“Who are you?”

Because there was something in his saviour’s hair; poking out where his ears would be. Something that looked like, and twitched, like fins. That wasn’t possible. Surely. Surely his mind was being ridiculous.

“Well—” The boy pulled away, looking Sherlock over. “I’m not a whale. Or a monkey sewn onto a fish.”

They were familiar words. His hand shifted, as well, down to Sherlock’s chest. Over his damp shirt, and racing heart. It was pounding for a different reason now; pounding because there was a beautiful face smiling at him. He shifted, managing to get onto his elbows. Managed see that he lay on a stretch of beach; scrubby plants to either side, the waves just beyond his feet.

And by his feet – his mind refused to believe it – a fish tail. A long, curving fish tale, the fin caught by the edges of the tride. The sun shone on the scales; they were vermillion. But in the light, there were hints of orange, of rose. In the shadows it was burgundy. Sherlock could watch it all day, but he trailed his gaze upwards. Saw the top of the tail, where it turned to the creamy skin of the boy’s stomach.

“I’m dreaming,” he said. This was not possible.

“Are you in pain?” The creature’s voice was soft, almost silky.

Sherlock nodded, and his dark hair was pushed back from his damp cheeks again. His chest still burnt and there was a dull pounding in his head.

“Then you aren’t dreaming.”

“Mermaids aren’t real,” Sherlock insisted.

The creature chuckled. A soft chuckle. His hand gently entwined with Sherlock’s, tugging it to himself. Sherlock’s hand felt heavy. His fingers brushed against the boy’s bare shoulder. The curve of his collarbone. The softness of his neck, and the line of his jaw. His fingertips disrupted the sparkling water drops there, turning them to rivers running down his skin.

“Am I real?” His saviour smiled at him.

Sherlock made a sound. Because now that his mind had woken up, now that he could see and think clearly, he realised the boy’s eyes weren’t brown at all. They were red. Like cherries. Like his ears and his tail.

This boy – this creature – this mermaid – was beautiful. Stunningly beautiful, and maybe it was because he was still half-drowned, maybe he was under some kind of spell, but he felt enchanted. Entirely drawn in.

“Perhaps I’m dead.” But he didn’t pull his hand away.

The mermaid’s hand shifted, so it lay over Sherlock’s chest. His palm was warm. “I can feel your heartbeat.”

“I’m delirious, then.” He arched into the touch. "Imagining things."

The mermaid chuckled. And did something that, to Sherlock, only confirmed his suspicions of delirium: he leant down, and pressed their lips together. He was warm, and tasted of salt. His eyelashes brushed Sherlock's skin, as he pulled away from the kiss, eyes glittering.

"Could you imagine that?"

It felt real. "No. I couldn't."

The mermaid's tail flicked. He felt it against his trousers and he felt a surge in his stomach. This creature was beguiling, and his kiss had made Sherlock's stomach leap. This was something out of a penny romance novel. Complete fantasy. Worse than that. The kind of explicit story that he would only read in private. It could go further down this route, if he lay back.

Did he want it to?

He pressed a hand to the mermaid's bare chest, pushing him away slightly. Those crimson eyes blinked at him; surprised.

"Let me make sure I have this right." He cleared his throat, and hoped it could help him clear his head. "A mermaid saved me from the ocean, because you've fallen in love with me."

"Love is a strong word." The mermaid touched the back of Sherlock's hand. Very gently, tracing down to his wrist. It sent goosebumps prickling through him. "I am intrigued by humans. By you."

Intrigued. The same feeling Sherlock had for the flora and fauna he was sailing to see. As though this was an experiment. He sat up properly, the swimming in his head beginning to fade.

The mermaid sat on the beach, his tail curled, as though an artist had drawn him. His hair shone gold in the daylight.

"Intrigued," Sherlock murmured. "You have an interesting way of showing intrigue."

The mermaid shrugged, catching a dark curl on his finger, and twisting it around. "You're very beautiful."

"High praise, from you."

The mermaid smiled. Their fingers nudged, in the sand, and Sherlock realised that he still had a palm pressed to the creature's chest. He stared. His skin was smooth and ivory. When he leant into the touch, Sherlock could see the lines by his ribs - deep lines. Were they gills? The mermaid took a breath, when he moved towards them, and the lines fluttered.

Sherlock let his fingers fall to the wet sand. His throat felt raw, and his head still too light. His chest still ached where it had been hit by the prow.

“As intrigued as I am,” the mermaid said. “You are unwell.”

“I could manage…” His mind was jumping ahead, and his gaze fixed on the mermaid’s lips. If he was delirious – if this was real – then he didn’t want to waste any time.

“You need rest.” Though the mermaid leant closer, as though he felt this same magnetism. So close that Sherlock could feel breath on his mouth. “There’s a cave, just around the bay. Could you make it there?”

“Not without you.” Sherlock grazed through blonde hair, gently taking hold of the strands, as though that would make him stay.

This creature, who smiled at him, somewhat indulgently. “I’ll meet you there.”

His lips grazed Sherlock’s. Just enough for him to lean forward, and manage to kiss him back, before he pulled away. Before his tail grazed Sherlock’s legs and trousers again, as he twisted away, easily over the sand, and disappearing back into the surf.

Sherlock saw a flash of crimson, above the water. It flashed again, to the left, and he realised he was being led to this cave. He managed to pull himself, with difficulty, to his feet. Managed to stagger through the wet sand, with his head still dully pounding. Now the mermaid wasn’t in front of him, he was sure he was delusional.

But his lips still tingled.

His imagination wasn’t that strong.

He found what was less a cave, and more an overhang. But it was shaded, with ferns springing from the soft sand. Very soft sand. He sat back down, his back against the rock, and watched the waves; the light on the waves; the sun was just beginning to set. That was good. It was much too bright, and much too hot.

He couldn’t be certain anymore, but there was another flash of crimson.

Then he had to give in to the pounding in his head.

Sherlock had dreamt it. He must have. Because when he awoke again, with a raw throat and raging stomach, there was no mermaid in sight. No mermaid to meet him. A delirious dream that had somehow led him to safety in the shade.

Because he was safe. Now his head was clear, he could see that he was on a bay of a large island. There was a forest, beyond the sand. He kept to the beach. Found coconuts and smashed them on the rocks, drinking their milk and going so far as to lick the flesh before he scraped that off with his teeth too. They were good fuel for the signal fire that he built where he’d washed up. He added leaves to it as well, to create as much smoke as possible.

Then he sat back under the overhang, and waited. Did not think of the beautiful face belonging to the beautiful creature. Did not think of those two chaste, fairy tale kisses. If he did, his trousers became tight.

It had been a fantasy. A dream. Because that sailor had told tales of mermaids, so it had all gotten mixed up in his mind.

But, in the late afternoon, then he saw something in the water. He first thought it was a shark, cutting through the waves towards him. But then a head emerged; a mostly human head, with sleek, golden hair. With glittering crimson eyes.

Sherlock met the creature at the start of the surf. Sat down as the mermaid pulled himself up, leaving the very end of his fin in the sea.

“You said you’d meet me,” Sherlock said. It came out accusing.

“And I have.” The mermaid pushed his long hair back, over ivory shoulders. His collarbone shone with drops of water, like a necklace of jewels. “I had to convince my brother that I hadn’t saved a sailor’s life. He’s not fond of humans.”

“You have a brother.” Sherlock watched a drop of water run down the boy’s bare chest, down to his naval. Even with a clear head, he felt attracted to this creature. It was his sparkling eyes and coy smirk; his softness contrasted with his boldness. He’d never met a boy like this, let alone a creature.

“Do you?”

“Yes.” Then Sherlock took in the second part of that sentence, and forced his eyes upwards. The boy’s crimson ones examined him, much too closely, shining like garnets. “Are you not supposed to save sailors?”

The mermaid chuckled. He reached out, catching a strand of Sherlock’s dark hair, and twisting it around one finger. “We’re supposed to drown you.”

“Then why didn’t you?” His fingers twitched, and grazed the scales of the mermaid’s tail. He felt it move against him. It was warm; the scales the size of his fingernails.

“Because—” The mermaid kept twisting his hair, until he had to lean forward to accommodate. Their faces were very close. “You call hunting a coward’s sport.”

“You listened to me.”

“I listen to many ships. Your conversation was interesting.” The boy’s eyes were half-lidded. “You’re interesting.”

Sherlock laughed. It felt light, and bubbly.

“To me, you’re interesting,” he replied. Dared to reach out his hand, and wipe his thumb over the boy’s collarbone. Felt the intake of breath under his touch. This was happening, then. They were continuing where they had left off. They were flirting, and that should have been absurd, but what else was he going to do whilst stranded on an island? With a beautiful boy who had his hand in his hair? “If you have a brother – do you have a name?”

“No.” He traced his fingers over the back of Sherlock’s hand. “But I like the name William. The first sailor I met was called William. It’s a nice name.”

Sherlock found himself smiling. He liked this one; with his knowing eyes and soft voice. With his slight smile.

“Can I call you William?”

The mermaid tilted his head to one side, catching the sun. “If I know what to call you?”

“Sherlock.” Sherlock leant closer to the mermaid – William, then, who buried his long fingers in his hair. “My name is Sherlock Holmes.”

Their lips brushed together, and Sherlock felt sparks dancing from the contact, as William whispered, “Sherlock Holmes.”

"I'm – not a sailor,” he whispered. “I’m on a research trip.”

William's mouth moved, to graze Sherlock's jaw. But only just enough to take his breath away. "What were you researching?"

Sherlock tilted his head away, his heart fluttering as surely as the mermaid’s tail. “New species.”

“I see.” He felt William’s lips move against the soft skin of his throat, then he dipped lower, nudging the collar of Sherlock’s shirt. “And what will you study, when you find this new species?”

Sherlock ghosted his fingers up the mermaid’s arm, past the curtain of silky hair. “Anatomy.”

"Remarkable.” William pulled away, his tail twitching eagerly between them. “I have the same interest."

They were watching each other's mouths. Watching the slow smirks growing there. Understanding each other.

Sherlock ran his fingers over the hollow of William's shoulder, his thumb tracing his collarbone.

"A joint investigation, then?" he whispered, as if this island was deserted. As if anyone could possibly overhear them.

William chuckled, breath warm on Sherlock's lips. "Quite."

Heat pulsed through him like a tidal wave. A tidal wave that sent him crashing forwards, his lips against William's. Their mouths opened against each other. The mermaid tasted of sea salt; felt soft, like velvet. He explored Sherlock's mouth greedily, his hands searching Sherlock's shirt, damp from the ocean spray. His fingers seemed to stick on every crease, sending sparks dancing across his stomach.

He pressed his palms to the curve of William's arms, round to his shoulder blades. They pressed against him as the mermaid pressed forward, humming in pleasure. His own back hit the sand once more, though he was only dimly aware of it; much more interested in William taking Sherlock's bottom lip between his teeth. Sherlock's breath shook.

William's thumb caught his nipple through his shirt

Sherlock's back arched; they were so close his chest brushed William's. His bare chest. This boy was so very bare, and his skin was warm; his hair shining with damp, his tails glistening. Certainly something from a Greek epic.

His hands tightened on William's back, feeling his spine shift under him.

William pulled away from the kiss, licking his bottom lip, as though savouring it. His crimson eyes shone. "Intriguing."

"What is?" Though Sherlock knew. He was arching his back, one hand clutching at the sand, feeling deliciously trapped.

"This." William's thumb pressed over Sherlock's nipple again. Caught the damp fabric of his shirt, sending sparks darting through him. His tail twitched, twined around and through Sherlock's legs. He toyed with Sherlock's nipple, watching his breath catch and the heat rise in his cheeks. "Your reaction. What is the purpose?"

Sherlock's fingers explored the mermaid's spine, and how it shifted under his touch. William's eyes watched him, almost lazily, shining with amusement. He kept up his slow torture.

"Pleasure." Sherlock smiled.

William chuckled, in response, dipping down to kiss him. Sherlock kissed back, pressing his tongue through to feel William's tongue; his teeth. When William pulled away, he made a sound in the back of his throat. It only earnt another chuckle, as William tugged open his shirt. Press just the tip of his tongue to Sherlock's nipple, before grazing the tip of his teeth against it.

Sherlock whined. He felt the tail tighten as if in answer. William's mouth was warm, his lips damp. His other hand pressed against Sherlock's chest. His heart raced against it, his he'd light enough to feel delirious.

William pulled away when he thought he was about to unravel completely. Smirked down at him, "Pleasure, indeed."

Sherlock's fingers tangled in long, golden hair. He smiled. "Humans are very sensitive."

"I can see." William smiled back. He pressed a kiss to Sherlock's chest, then moved lower. Let his warm breath fan across the hollow of his chest, down to his abdomen. His teeth grazed sensitive skin, tongue poking out just enough to get Sherlock's breath to catch. He twitched, soft sounds emerging from him without his permission. He heard, and felt, William hum in response.

Sherlock twitched, and gasped, and let silky hair fall through his clutches. Felt scales against his bare legs and it sent a rush of arousal all the way through to his core. And when he felt William chuckling, knew he had to resist this. Couldn’t lose whatever battle was occurring. He shifted, half sitting up. Tilted William's chin up, so that those heavy-lidded, crimson eyes looked up at him.

"And is it the same for you?" he asked. His voice was low. It was a tease - because surely, he knew this about humans. Surely, this was a tease, and he felt the same way.

William pressed his teeth against Sherlock’s thumb. Nipped it, lightly. Murmured, "Why don't you investigate?"

Sherlock's hand dropped to William's chest. Eased him round, and down onto the sand. His tail flicked up after him, hitting the back of Sherlock's shins. He looked more beautiful, if possible, sprawled on the sand. His tail was a lurid red against it, stray scales climbing up his skin. Sherlock ran his thumb across them, and William’s stomach twitched against the touch. His skin was only a shade or two lighter than the sand around him, his hair sprawled out, those red eyes watching him with interest.

Sherlock kissed him first. He had to, to taste the salt on William’s lips one more time, before his lips trailed down, though still touching his skin until his found William’s nipple. Took it between his teeth and - toyed with it. Enjoyed the soft sound that William made as he did; how he arched in the sand and took a handful of Sherlock's curls. Tugged it, once, and he felt the sharp pain through his scalp. It made a sound come from the back of his throat involuntarily. From William's answering gasp, he enjoyed that.

Sherlock investigated lower. Trailed his tongue down William's chest and stomach, to the line where his scales began. No bigger than his fingernails, glistening in the sunshine. They were beautiful. He traced his finger across them, and William's tail shifted in response.

"This is where we differ," he said. "How sensitive are you, down here?"

William tilted his head, from where he lay in the sand, smirking. "That's for you to discover."

Quite, Sherlock found out. His fingertips earnt him twitches, and his mouth earnt gasps. The join on his fin was particularly sensitive. William whined, and keened at the tiniest touch.

Sherlock couldn't help smiling. His heart raced like music in his ears, his mouth tingling from the rough sensation of the scales. His own desire was a growing, heavy knot just below his stomach. He clenched his legs together in an attempt to hide it.

It wasn't successful. William was watching him, perched on his elbows. He flicked his fin against Sherlock’s side, reaching down. He palmed Sherlock’s crotch, his eyes glittering.

“Your body intrigues me.”

Sherlock’s breath hitched. It felt absurd to feel embarrassed, but his cheeks still flushed with heat.

“Tell me why that’s happening.” William’s voice was soft. His fingers twitched, and Sherlock gasped.

“I think you know,” he managed to murmur. Because surely he was not the first sailor this mermaid had studied anatomy with; he was too skilled for that.

“I don’t,” though the smirk at the corner of William’s mouth said otherwise.

“You.” Sherlock couldn’t help pressing his hips into William’s touch. It didn’t relief the need at all – it made it worse – he could feel each of William’s fingers pressing into him. “This. I’m aroused.”

That smirk widened. William pressed a kiss against Sherlock’s cheekbone. He kept his face close, his lashes brushing Sherlock’s skin. He kissed against his jawbone, whispered against his throat: “Can I see?”

As if Sherlock could argue. His fingers dug into the fish scales underneath him. He nodded, his hair falling into his face. William brushed it back. Sand stuck to his bare chest; to his fingers; he found the tie of Sherlock’s trousers. They fell open, and William eased them down. Exposed Sherlock’s need. He watched William’s expression, as he examined it. The interest and the satisfaction and his own desire.

His fingers stroked down his length, lightly; Sherlock’s hips bucked like a donkey in response. Those fingers went lower, exploring. Researching anatomy. That was what they’d said. The reality of it made Sherlock whine with arousal, his heart racing.

William’s tail flicked against him in answer. “What now?”

“Now—” Sherlock tried to smirk. It was hard to, when his heart was racing in his ears, and he was leaning over a mermaid on the beach. When this felt like something from a erotic fantasy novel. “You show me yours.”

But William was smirking back. The lower part of his tail twisted between Sherlock’s legs as he pulled him closer. Water droplets sparkled on his collarbones like diamonds, and Sherlock pressed his mouth to them.

And the studying, Sherlock thought, truly began.

They’d lain on the sand together, afterwards. Sherlock had lay with a mermaid on his chest, toying with his damp, dark locks. It was hard to catch his breath; his pulse still drummed in his ears, as constant as the tide. It lapped at his legs – his trousers were still undone – at William’s tail; the water was cool compared to the sun above them.

“You’re a fine sailor,” William murmured. He nipped at Sherlock’s collarbone, and he hoped that it would leave a mark. Then he would have a souvenir that this had happened.

“And you must be a troublesome mermaid to your brothers,” Sherlock replied, stroking his fingers through William’s long, golden hair.

William chuckled. “As enjoyable as sinking ships is, I much prefer this.”

Sherlock didn’t quite laugh. It had been easy to forget what William was – what he said mermaids did – whilst they had been wrapped up in each other. Now, he felt a shiver up his spine. He was laying with a predator; a killer. Perhaps he was in danger all over again.

But as it grew dark, William slipped back into the water. His brothers would be missing him. He left Sherlock on the beach, with a long, final kiss. He heaved himself to his feet, his clothes heavy with sand and sea salt.

At least it was a full moon. He spent the night re-building the signal fire; spelling ‘SOS’ on the beach. There were plenty of bone-dry leaves that created a thick, dark smoke. He sat on the beach, pressing a finger against his mouth, and remembering William’s. Remembered kissing the gills on his ribs. Remembered going lower, and discovering the secret of how mermaids procreated.

Useful, scientific insight, he was sure. Though he had been distracted by William’s beautiful face. Had been distinctively unscientific when that pretty face, with that pretty mouth, had pleased him, red eyes glinting up at him in amusement.

William came back. They continued their anatomy research. Lay against the rocks together afterwards, and Sherlock told William stories about London, and England. William told him of underwater palaces, and he was sure that he was being teased.

Eventually – after two days of surviving off coconut milk and seared fish – Sherlock’s ship found him. He was welcomed back on deck and told he was a very lucky man. Sherlock smiled back at them all, because he could see a red fin disappearing into the waves. A lucky man, indeed.

John hugged him. Tight enough to squeeze the air from Sherlock’s lungs. He pulled away.

“I’m so glad we found you!” he cried. “The men all told me there was no hope, but I—” John ducked his chin to his chest. “I wouldn’t let them.”

“Thank you, John.” Sherlock caught his hands, squeezing them in his own. Another sailor put a blanket around his shoulders – his shirt was torn, and he was consistently sprayed through from the ocean. His shoulders and cheeks had burnt from laying in the sun. “You’re a good friend.”

John’s cheeks were pink, and his eyes shone. He kept grinning back at Sherlock.

“I’m really alright,” he said, as they were led across the deck. Bedrest, the Captain was saying – Sherlock needed lots of bedrest, and a proper stew, and a good measure of rum. “I survived.”

“Of course, you did.” John stayed by his elbow. Of course he would, and Sherlock was glad to have him back. “It looks like you got your adventure after all, Sherlock.”

His mind conjured up William’s red eyes and sparkling scales. The way he’d tugged Sherlock’s hair when they lay together; his tail wrapping around him.

He smiled back at John. He knew he couldn’t say what had happened. They would call him delirious – and maybe he was. William would have to stay a secret. So, instead he said, “Oh, absolutely.”

After all, he’d found his new species.

And maybe, he’d see William again, one day.

#turnupswrites #sherliam #yuu no mori #yuukoku no moriarty #william james moriarty #sherlock holmes #fanfiction #fanfic #im still stuck on these idiots #mermaid au #au

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