Hello lovelies! I started this fic a while back and thought it would be a perfect upload for Halloween!
Please forgive any incorrect nautical terms, my knowledge on seafaring is limited and I could only do so much research :P (Ships are much, much slower than I ever expected by the way)

The Siren looks like the cover pic pf this story, the full picture can be found on my tumblr account and one embedded in the Chapter on Archive on our Own. It was made using a combination of editing tools and hand drawing with the base picture I used being a screenshot of one of the Sirens in Witcher 3. Sadly FFN doesn't allow the posting of links, nor is embedding visuals here possible so this is the best I can do.

Enjoy and happy Halloween!


Chapter 1 - The Arrival

The drag and pull of the waves was hypnotising. Jagged rocks faded in and out of view amidst the spray of stormy water. A low, impossible fog that hovered right above the waves and weaved itself between the black spikes impaired the vision further. And there, bubbles rising to the surface, the water stilling as if in slow-motion as his gaze was drawn further inwards. A white shape in the depths below, a negative imprint of a moving shadow. He leaned further across the railing to get a better view. Another flash of white-

"Captain? Captain?! HARRY!"

With a jerk of his head, Harry stumbled back from the railing, feeling dazed as he looked over his shoulder to his first lieutenant "To-To starboard, Ron!" he stuttered when finding his voice, casting a bewildered glance back at the rocks. "They're too close, we might jam into one of those nasty stones. Wards or not, our hull might not withstand that impact. Hermione, how's the distance on your side?"

The woman lifted her wand and shot green sparks to indicate all was good. With a swing of the steering wheel, Ron turned them away from the treacherous waters. The ship creaked and groaned, the ocean making a sucking noise as if wanting to keep them there, wishing for them to collide on its teeth and drown.

Harry shook his head, he'd probably drank too much the night before. It had been quite the celebration, after finally losing the Kitten that had been trailing them since leaving port. An innocent name for the most hated vessel across the known seas. Its pink sails were a warning to all who dared sail out without registration. But registration meant bowing to the Ministry of Magic and considering that a great deal of Harry's crew consisted of 'illegal' Muggleborns, he wasn't about to betray them like that. Ron stepped aside respectfully as Harry took back the wheel himself, instead going to check on all the knots to ensure there was no damage anywhere.

They were getting to the heart of their mission now. Harry grasped the locket around his neck tight, feeling the metal pulse respond. Two years of preparation, of research and long talks with the aged pirate lord who'd mentored him. Two entire years of finding a ship and crew, small missions to aid the helpless against the Ministry's outrageous laws and larger ones warding off the ghost crew that came and vanished with the fog on a ship that looked like it had risen from the bottom of the ocean. And now, at last, Dumbledore had entrusted Harry with the last pieces of the puzzle to lead them into the heart of that cult, the Death Eaters… said to possess dark magic like no other, serving the elusive god who'd given them their powers. No longer would innocents disappear without a trace once that lot had finally been conquered.

Dumbledore had done the same in his time, at least according to rumours (unconfirmed by the old man himself, yet never denied either). The Acolytes had been much the same, terrorising the night under the name of Lord Grindelwald. Only Grindelwald had been human. Harry wasn't yet convinced that He-Who-Must-Not-Be-Named was too. None had ever seen his face, after all. They only knew of him from the one Death Eater that had ever been captured, the runt of the lot who'd hid as a sewer rat to scout. It did show the miraculous influence of this 'god', if its given magic enabled even such a spineless man to perform Therianthropy, a feat previously only mentioned in myths and fairy-tales like Babbity Rabbity. To transfigure the self into an animal… It was a shame the rat was promptly given a Dementor's Kiss, before any truly useful information had been extracted.

He touched the locket again. A compass to show the way, Dumbledore had mysteriously said when handing it to Harry without further explanation. The metal should show signs of wear for having allegedly been fished out of the deep sea, but it looked brand-new. Lively. Harry felt it was restless, more so as they approached their goal slowly but surely: The hide-out of the nameless ship with its striking serpentine decorations, the coves of Hangleton. They too, were a myth, an impossible goal not shown on any charts. In this direction were only the wild waters with sharp reefs of basalt that sliced through any hull like butter, whirlpools so wide it could drag down entire ships that weren't wise enough to turn around.

Yet, this was exactly where the Locket lead them, so he wouldn't back down now. They had two excellent warders to protect them: Bill and Fleur, and every single person Harry had hand-picked was more than capable of holding their own on either sea or land. Together, they were Dumbledore's army, for it was the ancient pirate who'd inspired this quest.

That and vengeance, a burning vengeance Harry would admit only to himself. There was no name to the face that haunted his nightmares, a woman with wild hair and wilder eyes who'd murdered the man who'd been a father to him. The Padfoot had been on the way to Iceland on a trade mission and Harry had begged for days to join Sirius this once, claiming he was old enough at fifteen to help out the crew. As usual, Sirius hadn't been able to resist his godson's pleading glance.

They'd been caught in a storm not two days after leaving Hogsmeade's port, before even reaching the Faroe Islands. It was a well-travelled path, nothing that should have caused trouble. Until it showed up: a black spire cleaving through the sleets of rain that flooded the deck, the figurehead a gaping skull that threatened to swallow a wide-eyed Harry whole who'd refused to go under deck in case anyone needed help.

She'd stood at the helm, features stark whenever illuminated by lightning that they had appeared to have summoned. Black hair loose, wheel in one hand, wand in the other and a crazed grin on her face as heavy-lidded eyes zoomed in on Harry.

'Ickle Potter' she'd cackled. To this day, he had no answer as to why she knew his name.

It had only mattered to him for a second. Before Sirius had saved him by jumping in between. Before the flash. Before the body had gone overboard, an ever-thickening veil of water covering his face as Harry screamed, held back from jumping after the man only by the strong arms of Sirius' best friend and lieutenant.

They'd left as quickly as they'd come. It had only been a game to the Death Eaters, to wreak havoc and destruction in their wake, a trail of corpses to claim these waters as theirs. The route hadn't been used since, the next ships moving around a wide arch to reach the islands instead, losing days.

Something had to be done. Someone had to jump straight into a possible ambush if they ever wanted to be free. That someone was Harry James Potter.


Their speed slowed down to a single knot as they attempted to navigate through the shallow waters, until finally they were stuck with nowhere to manoeuvre but backwards. Turning the sails the other way would take ages, even with magic. Harry set most people on that task, inviting Ron and Hermione to the Captain's cabin to discuss.

"Is this it? Have we arrived? Or are we just stranded on a deserted rock?" Hermione asked, eyes worried as she bit on her lower lip. Her eyes fluttered to the heavy locket around Harry's neck as he closed a hand around it, listening to the heartbeat.

"This seems to be it," he spoke with great unease, having had chills run over his spine for the past day. "I'd expected it to be less…. Less empty. Lair of the snake and all that." He'd imagined a great, heated battle with the Death Eaters upon arrival, or traps at the very least. There was only the ominous sound of the black ocean that surrounded them.

"They have a ship," Ron reasoned. "Doubt they actually show up much at their base when they're out there so much. There are sightings each day, even some as low as the southern coast. Whatever magic they use to up their speed, it took us two entire weeks to get here from the very tip of Scotland. We might need to wait a long time before they arrive. Best use it to prepare our ship for take-off again so we are ready to leave as soon as they land here and we defeat them."

Ron always sounded to certain of their victory. All of the Weasleys did, a necessary comfort on such a precarious journey. "Let's go explore the coves," he decided, wanting to do something. "We can set up rune wards and hiding places to ambush them when they arrive. They'll know they have company with the Prongs anchored here, but that doesn't mean we can't have a surprise advantage at all. Plus, maybe we'll find some treasure or useful information in there."

'Some' turned out to be a major understatement. The Death Eaters clearly had never expected their foes to find these caverns, as Galleons and valuables aplenty were carelessly piled on heaps, spilling across the stone of the very first cave they entered. Harry split the crew into tasks: some continued working on getting the ship to sail backwards, some carried the stolen treasures towards it to fill Prongs' belly, while a chosen few went deeper into what turned out to be a maze of mysterious grottos. It appeared engulfed by the sea itself, crusts of salt and barnacles growing on the dripping walls. Some held craters filled with still water, and when Harry peered into them, he saw a wealth of unexpected flora and fauna, miniature aquaria of marine life he would have expected to find in the gulfs of India or the Chinese sea, not this far north. Unthinking, he dipped a hand into one of the pools, stumbling back as a fanged fish shot out instantaneously in an attempt to make his fingers into its next meal, but not before noticing the water was indeed hot.

The voices of his crew grew dimmer as Harry pressed on, finding wonder after wonder, magic growing heavier with each step as he spiralled around the caves, ever deeper towards its centre.

He came to a halt in front of another pool. His Lumos maxima was reflected by both the pitch-black water below and numerous crystals above. The locket grew hot around his neck, which he barely noticed, entranced as he was by the beauty. With a feeling of deja-vu, his eyes were drawn to a stream of bubbles that disturbed the mirror-like surface, tiny ripples forming. Harry leaned closer, crouching down at the edge. There it was again, a white shadow, the same from yesterday. It elegantly curled and twisted in the deep, too fast to catch a proper glimpse of. The locket fell from out of the fold of his robes, hovering half an inch above the water, subtly pulling…

One moment, Harry had been peering into the ripples in an attempt to see what mystery was hiding in here, the next said mystery shot up, breaking out of the water. There was no time at all to jerk away, bone-white arms encircling him, a flash of sharp teeth and red eyes all Harry saw before he instinctively shot off a stunner. The creature cried out – more in anger than pain – and disappeared into the depth again with a splash.

"What in Merlin's name-" Harry breathed, scrambling away. "Ouch," he muttered, pressing a hand to his shoulder, finding it sticky and warm. Teeth had sliced clean through his robes and nicked at the skin. As he looked at his fingers, they were covered in more blood than should be possible from such a shallow cut.

"Here you are! Harry, don't go running off like that!" Ron's voice echoed off the walls of the chamber. "I mean, Captain, Sir. Found anything?"

To not worry Ron and hide his own folly, Harry rearranged the heavy cloak he wore to cover the wound and quickly wiped his hand on the wet gravel to get the blood off. "A dead-end, it seems," he rasped out, uncertain why he wouldn't warn the others of the danger lurking in these depths. He felt dizzy. "How is everything on your end?"

Without glancing back, he returned the way he came, not seeing the creature silently gliding out of the water. A handful of red gravel was raked into the pool by a clawed, pale hand.

Upon returning to the rest of the crew, it became easier to breathe again. Quite literally, it felt as if his lungs could draw more air than before. The caves were devoid of gems and gold now, all stowed away in Prongs' belly. Good, they'd need gold to convince the goblins to aid them in their rebellion. Also, the Weasleys just plain deserved it after having been cheated out of a livelihood by the horrid toad. If they'd cross the Kitten on the way back, perhaps they could make some use of the Weasleys' experimental cannons. He hadn't wanted to risk it before their journey had even properly started.

The treasure being gone wasn't the only change. Lavender, Parvati and the Creevey brothers were all excitedly chattering, lifting their illuminated wands higher to cast light onto a series of drawings that spanned the cave. White and red lines on a dark canvas of shimmering rock. Harry's breath caught again as his eyes trailed over the images of a pale, sleek creature.

"They were hidden by a layer of wards," Hermione informed him, quick to jump into an explanation as per usual. She sounded breathless too. "I theorise that this is it. Their… god."

The captain tore his eyes away to give her a disbelieving look. "This is He-Who-Must-Not-be-named? The source of their power?"

"Likely an ancient creature. From the features I'd say either a type of merman, siren or sea wraith. All of those possess magic, though I haven't heard of one being able to pass powers onto humans. Nonetheless, do you see the drawing over here?" Harry did, staring at a spiral that he imaged to be a stylised whirlpool. In it, streaks of red, above it the creature with arms stretched out. "A ritual of offering," she whispered in awe. "Old blood magic, they perhaps formed a pact with it. I wonder if it travels with them."

No, no it didn't , Harry thought, feeling the urge to call everyone back to the ship into safety.

But he wasn't here for this being. He was after those who used its power, after the woman in the storm who'd murdered Sirius. He started pacing back and forth without noticing, brooding on his options. The Death Eaters were whom he wished to defeat, who got their abnormal, dark magic from this being. Without it… would they be powerless without it?

Making up his mind, he started giving orders, by now finally used to his role as their leader, their Captain. He hadn't wanted to take up the position at first, but as Dumbledore had pointed out, it had been Sirius' greatest wish for Harry to get a ship of his own and the usually so irresponsible man had saved a great sum of gold to reach that goal. Naturally, there was no denying the will of the man who'd raised Harry as his own after saving him from the Dursleys at age 5.

Once everyone had a job, either guarding the ship, counting the money or scouting the outsides of the island, Harry announced to his two lieutenants that he would be gone for a while and promptly turned on his heel to march back into danger. When reaching the centre this time, he stood a while away from the edge, pondering on how to draw attention to himself without becoming a target. Checking the nick on his shoulder, he saw the blood still hadn't formed a crust. A type of poison was into play for certain, which meant it was a bad idea to cast a general healing charm on it. Their only apt healers were Cedric and Terry, both of whom were prone to fuss over him and ask questions he did not yet wish to answer. Not until he knew it was safe for his crew to approach this thing too.

"Lumos Maxima," he spoke, figuring that the light would be a politer way of announcing his presence than throwing stones into the pond. He cast the orb of light into the middle of the room, letting it hover above the pool. At once, he was greeted by a stream of bubbles. Something pulled at him, but Harry was more prepared this time, digging mental heels into the sand. His eyes hushed over to the place he'd knelt before. Something had left marks, he noticed, hairs on the back of his neck prickling.

It took every fibre of willpower he had not to approach the edge as a shape became visible, lazily floating closer to the surface, a brilliant white silhouette moving a mere foot below the surface, which barely welled up at the languid movements. Harry's heart hammered in his chest as he took off his hat and pressed it to his chest, stiffly taking a formal bow. He wasn't very apt at formal manners – not when growing up with outcasts and Muggleborns – but many creatures that preyed on humans studied their mannerisms and appreciated good etiquette. Rude jerks were much more likely to get eaten by hungry merfolk, every sailor knew that.

He waited like that for a good while to see if the creature would deem him worth paying attention to. He refrained from speaking, firstly as there were contradicting tales whether merfolk and sirens could understand human tongue and secondly as the water between them would render his words inaudible until the creature would surface.

"Back so soon?"

Harry's head shot up, not having heard the slightest sound before. And yet, there it was, casually leaning over the edge of the pool. It didn't much look like the carvings and paintings of sea folk Harry had admired as a child. It barely resembled something humanoid, though the intelligence in the blood-red eyes that gazed at him was unmistakable. Harry's gaze dropped to the creature's pale hands. Its nails resembled razor clams, long and deadly.

"You've been following me," Harry accused. "Haven't you?"

"I do not leave my home defenceless when ships breach my waters," it calmly replied. "What brings you to my dwelling? Surely not the sights."

Telling the truth wasn't a smart move when it was still unclear whether this creature was an enemy or if it helped the Death Eaters unwillingly. However, Harry was a pretty shit liar, for a pirate.

"The people you made a pact with… they're raiding villages. Plundering ships and leaving the crew to the ocean. Were you aware?" he asked. There were many tales of heroes and villains tricking beings into sharing knowledge or getting their hands on invaluable goods. What if this 'god' had been tricked and used?

It cocked its head, unblinking stare directed at Harry with interest. "Humans are as plenty on land as fish in the sea. My Knights bring me food, I give them power to gather riches. However they obtain those is not my concern. Do you blame the smith for the people who die by your sword?"

"I wasn't accusing you," Harry hastened to correct. "I only… I only wished to know." So although the Death Eaters raided in its name, He-Who-Must-Not-Be-Named didn't appear to care all that much nor ordered these murders. Good. Harry shouldn't lose focus on his true goal, then: getting rid of the Death Eaters. He struggled for a moment to find a polite way to end the conversation. As interesting as this creature was, it didn't seem to be that mobile, confined to its pool here and the ocean beyond. There should be no way for it to interfere.

"Are you thinking of leaving?" It sounded amused. Harry didn't have much of a chance to reply as it heaved itself further out of the water to sit at the edge, shimmering scales catching the light. Harry's eyes involuntarily drifted across a heaving ribcage, the dip of its stomach and the spiky fins adorning the base of that beautiful white tail. The wind that had softly howled through the cave complex changed its tone: it became deeper, richer somehow. Harry shook his head in confusion and took a step forwards, in the direction of its pleasant hum. His body ached for the melody to soothe it, the cold pleasantly disappeared as notes wrapped around him. A hand reached out, a sharp claw that glinted in the now dimming orb of light he'd cast before. There was a prickle of warning in the back of his head.

"No!" Harry willed himself to stop, to scramble back as the spell broke. The light grew again, fully illuminating the fanged snarl on the siren's face. His heart was hammering. So it was a siren, and Harry had almost been careless enough to be lured into its waters.

"Such willpower," it rasped, eyes glowing with an emotion Harry couldn't name. Perhaps it was one unfamiliar to humans. "Tell me, Captain , what do you see when you look at me?"

When Harry finally found his tongue again, he said: "I don't understand the question. I see you, of course."

"And what do I look like?" There was genuine curiosity in its voice, which halted his resolve to leave.

"Do you not know what you look like?" he questioned in confusion. "You are… pale," Harry said, attempting to find neutral words that would neither insult it nor betray how oddly pleasant he found its appearance. "Gaunt and sleek. I'd alike you to a sea dragon, for you compare to neither man nor any animal I've seen with my own eyes before. And your eyes… they have the colour of blood."

Whatever the Siren had expected, it hadn't been this, judging by its brief expression of utter surprise. "You see me as I am?" Then, needle-teeth were on full display as its laugh, a melodic sound that rattled the crystals on the ceiling, echoed through the cavern. "My, you must truly love danger, my bold Captain. You have intrigued me."

"Is… is that a good thing?" Harry asked, eyes flicking to the entrance behind him, attempting to calculate how many seconds it would take for him to sprint towards it while still being careful enough about his footing not to slip on the gravel.

"An excellent thing," it hissed. "Perhaps I'll treat you to that which few of your kind have ever heard before…"

Harry only glanced back briefly enough to see its eyes were closed now and the Siren was swaying back and forth. He dug his right foot in the sand, muscles ready to jump-

"Softly the waves, that you dearly crave
Give you a place to disappear
Let your life fade, and don't be afraid
No memories are needed here…

Touch onto the sand
Reach for my hand
Answer the call from the deep
The light high above
That you once so loved.
Fades as you drift to sleep

Embrace me now…
We will be one…
I whisper my call
To the world you'll be gone

So dream of my voice
for you'll have no choice
But to echo my call from the deep"

Harry awoke with a shock as the melody faded, taking a large gulp of the seawater that surrounded him now, head barely above the surface. As his brain caught up to tell him that he was submerged into the Siren's den and scaled arms had encased him, pressing the air out of his lungs, Harry started struggling. There was no panic, exactly. He'd been in enough tricky and outright lethal situations to not easily lose his cool. He elbowed the creature to loosen its grip and kicked his legs out from under him in an attempt to get closer to the shore again.

Predictably, he didn't get far. His entire body felt sluggish from the freezing water and it didn't help that the one who'd dragged him in here was much more agile and faster than a sputtering, splashing human. "Now where are we going?" the Siren darkly asked, wet lips pressed against Harry's ear as arms tightened their grip again. With a lazy wave of the tail beneath them, they drifted to the middle of the pool. Harry attempted to hold still, as it wasn't attempting to pull him under, at least.

"What do you want?" he coughed, attempting to expel the water from his lungs. The salt stung like crazy.

"It's not often that one breaks my spell so instantly," came the non-answer. The grip shifted so he hung into one arm. Terrifying claws of the other trailed down Harry's cheek. He hissed at the sharp pain. "Your blood is by far the tastiest I've had in recent memory…" it whispered. Harry turned his head the other way as a long tongue licked the drops from his face.

"My crew will come find me soon," he warned. "If you kill me, they'll have your head."

"Killing you hasn't been on my mind since you resisted my first attempt," the Siren admitted. "That doesn't mean I don't want to get a taste of you. Your crew cannot interfere, Captain. You entered my domain." The edge of the cold tail came up and wrapped around Harry's legs. "And I've found that you don't shy away from danger, do you?"

"I… I don't know what you-" he stammered, for once flustered as the creature's heavy body slotted itself against his back.

It didn't remain at that, a pale hand leaving his face to slide down his chest instead, cutting open the fabric. "Come now, don't be so coy, my handsome sailor. What I want is only a reflection of your own desire."

Vehement denial was his first instinct, until the hand crept even lower and Harry had to swallow his words. Danger, flashed through his head. But wasn't that everything he'd ever wanted in life? While his best friends had swooned at the thought of pretty Nixies and handsome selkies, Harry had secretly been far more intrigued by the possibility of getting seduced by the sea horrors portrayed with too many teeth and tentacles. Sirius had endlessly poked fun at him when Harry had let slip that he found the Kraken on a moving painting the man had brought home about a year before his death, to be alluring rather than horrifying. He'd never breathed a word about his dark fantasies to any of his friends. And now he was here, in the vice-like grip of a creature that looked like it had been shaped by the ocean itself to be its most deadly predator. To boot, its voice was quite literally to die for.

"Ah, I am right. Humans betray so many of their thoughts by their breath, it's fascinating."

Harry's muscles slowly relaxed as he made himself ease into the embrace. The cave around echoed his own shaky breaths back to him. He flushed when hearing the first moan that escaped his own lips in the moment that devilish hand smoothly slid into his pants to continue the fondling on naked skin with a surprisingly tender touch.

"Do you – ah, there - treat all of your -hnggg- victims this way?" he panted, not even attempting to pretend he was fighting this.

"Don't be ridiculous, most aren't worth my time. I show them what they wish to see, it doesn't go much further than that. Does it make you feel special to know that you are one of the few I'd rather fuck than kill?" it purred, pointy teeth scraping over the still tender wound at Harry's shoulder, which lay bare now his shirt was all but tatters. The Siren did drift closer to the shore now, but climbing out was the last thought on Harry's mind. He grasped onto the edge only to get a better grip and a smidge of control back on his own ability to move. Two hands now wandered freely across his body, caressing without cutting, pushing his pants ever further down until they floated around his ankles, cupping the cheeks of his arse before exploring the hollow of his thighs. Moaning again at the ministrations, Harry let his head sink onto the stone edge, uncaring about the pebbles digging into his face. Odd that he could be so turned on despite the cold. He didn't even have goosebumps and his previously frozen limbs felt more alive with each touch.

"Are you heating up the water?" he asked, confused.

The Siren chuckled and pressed itself close again, cold tail curled tight against his legs from behind. "It may have been ages, but I do remember how sensitive you people are. It wouldn't be much fun if you're a shivering wreck. Not to mention if you'd lack the capabilities of this." It emphasised the word with another squeeze of Harry's hardening cock. "I want to make this last , Captain," it sultrily hissed. "To explore your willing and eager flesh to the fullest. Your are eager, aren't you?"

Harry half-heartedly groaned, barely listening to the words as he was far more focused on attempting to rid himself of the last piece of cloth so he'd fully feel those sleek scales against his legs. It appeared this was not enough, as he got another painful bite to the neck. "Ouch! Hey!" he exclaimed, though he did not dare turn around as the hand stroking his erection never slowed and he did not wish it to either.

"Are you?" the Siren growled, lapping up the blood slowly.

"Yes. I mean... very. Err… the question?" he deliriously muttered, bucking his hips back in order to press his arse snugly against the Siren's nether region.

"Humans are hopeless," it sighed, then spun Harry around with one swift movement so they faced each other. Unfairly, the Siren's powerful tail enabled him to rise much further out of the water so he towered over Harry, entire gleaming chest exposed. The pirate swallowed hard, eyes hushing over the patches of scales on its arms and heaving ribcage. The water and bony side fins unfortunately didn't yet reveal what lay beneath. Leaning on the stony edge with an elbow now, Harry attempted to keep the other close by wrapping his legs around its tail. The Siren allowed being caged in - likely as it could break free any moment - eyes never leaving Harry's emerald ones. Boldly, Harry decided he wished to sate his curiosity, trailing fingers down the perfectly smooth belly to the base of its tail and dipped into the water. Beneath a hard ridge, he found smooth folds from which a sticky shaft protruded, which clearly grew larger as Harry enthusiastically fondled it.

A hand shot out to snugly wrap around his mangled neck. "Not so fast," it spoke with amusement, leaning down to claim Harry's lips. The pirate reluctantly let go, not regretting it for more than a second as a tongue plunged into his mouth. It was cold, impossibly long and absolutely delicious, Harry decided, wrapping his arms around the Siren's neck and shoulders so the kiss would not be broken. Harry's breath hitched as his own tongue was sucked into a mouth with sharp teeth that raked across it. Heart fluttered as he realised just how entirely at its mercy he was. One wrong move… the thrill made him even more flustered than before.

He was pressed against the edge as the Siren put in its full weight, rolling its hips against Harry's own in slow, decisive movements, a sticky erection sliding over his with each grind. Their lips never left each other's, nor did the hand release his throat, grip tightening each time their cocks met. The lack of oxygen in combination with the fire in his belly was enough to make Harry go dizzy. He only woke slightly from the stupor when a hand wandered down the back of his thigh and slid between his arse cheeks.

He withdrew from the kiss and stammered: "Your- Your nails are a bit sharp. I'm not sure…" For while he didn't truly mind the outside wounds much, he didn't feel like being sliced up from the inside. The Siren did not verbally reply, face splitting into a grin. Then, in a flash, it broke Harry's hold and disappeared under water again. "Wait, I didn't mean to end this completely!" he shouted in frustration. "Way to go Harry," he muttered to himself as the Siren's form disappeared into the depths. He turned around again and was about to heave himself out of the pool, when two hands firmly grabbed his hips. Looking down, he saw that the creature had returned, swimming underneath him.

He had no time to question the move, insides melting as the tongue that had previously explored his mouth started lapping at his hole. "Oh yes… yes yes yes," he mumbled, letting his head fall down on the edge again, barely keeping himself together enough not to slip into the water as hands forced his legs apart wider and the long muscle slid inside. The unbearable itch of needing to be filled up abated slightly as the Siren's tongue tirelessly plunged in and out for minutes. Teeth pierced the flesh around it, but Harry hardly cared at this point, reduced to a blubbering mess at the wonderful feeling of that wicked tongue that reached ever deeper. He reached down to give a modicum of release to his painfully stiff dick, but it was instantly pulled away and, possibly as punishment, the Siren slid out and submerged from the water, bright eyes staring at Harry.

"Did you enjoy that, captain?" it whispered, hungrily taking in Harry's flushed cheeks. A thumb wiped away a strand of saliva from the corner of his mouth. "From the moment I lured you into my pool, I wanted to lick you between those lovely legs until you cried."

The heated words were almost enough to send Harry over the edge. "Please just fuck me already," he begged, throwing all pride into the wind.

"You'll need to service me first. I wish to know just how long you can hold your breath," it spoke with a very sadistic smile, hand grasping a hold of Harry's hair and pulling him back into the water, swimming away from the shore.

Having a feeling what he was expected to do, Harry managed to take a last gulp of air before he was pushed under. The Siren wasted no time, one hand still fisting his hair, the other cupping his chin to guide him to the erection he'd felt up before. It was an odd, disorienting feeling, the Siren pushing into his throat before Harry knew what was up or down. It fucked his mouth mercilessly, and all Harry could do was try not to swallow water or attempt to breathe. His jaw ached, but the experience felt so right too. To be used for pleasure by this enchanting creature. Just as black spots started dancing in his vision, he was hauled up again, allowed to take in air for a second before being plunged back into the water, lips instantly sliding over the large cock again. And again. Harry lost all sense of how long this game went on. He was sure his face was bruised from the tight grip and the way it rammed inside. By the eight or ninth (or tenth?) time, the expected dip back into the water didn't come. Lips were back on his, arms wrapped around Harry's torso and the throbbing erection instead prodded his arse. Harry cried out as it pushed in deeper with wild movements, the previously so charming Siren now reduced to nothing but a beast driven by primal needs. Its growls joined the chorus of echoing cries as it filled Harry up, hammering away to reach completion. It didn't take long before a wave of shockingly warm seed was released inside of him.

Panting harshly, the creature slid out, a white stream drifting around them in the water. The knowledge of that they were floating in its semen made Harry's own neglected cock twitch to life again, even as the rest of his body ached from the rough sex. He let himself be pulled back and heaved up to the shore, cold wind hitting his body. The Siren unabashedly spread Harry's legs and studied the weeping manhood that sat in between, precum leaking out. A gentle hand cupped his balls, fondling it to see Harry's reaction. It was only in that moment that he realised he hadn't felt any testicles on the Siren.

He didn't have long to think further about the other's anatomy as the creature dove in and its tongue wrapped itself around the shaft. Harry leaned back on his hands and spread his legs further to give better access. Every single fibre of his body was on fire and he trembled all over when he was granted release at last. A smaller spurt of cum followed the first as he took in the sight of the mighty Siren swallowing down.

"Rather sweet," it commented with a roguish grin that would have stolen anyone's breath away.

Harry grunted, unable to form a coherent reply as he rode out the waves of pleasure. Only after lying there for a while, did realisation dawn that he'd been gone for quite long, and in the distance he could hear the shouting of his name. vI have to go back," he sighed in regret. Then, he shot up. "My wand! My clothes!"

The Siren chuckled and pointed to a spot behind him. "Be thankful that I made you drop your wand before you wandered in here like a helpless sheep," Embarrassed, Harry scrambled up to grab the beloved holly wand, then realised that – apart from the cloak that was still lying at the edge of the pool as well, all of his clothing had been shredded and disappeared into the ocean. He wrapped the cloth around him as well as he could and eyed his wand miserably. "Oh no, I suck at transfiguration… this is going to be difficult to explain to my crew."

"Then don't. Stay here with me for a little while longer."

Something in its voice made Harry pause and really look at the Siren. "Do you have contact with others of your kind?" he asked.

It shook its head briefly. "They know to stay away from me is healthier. My only regular company are my followers."

"Sounds lonely." Harry retraced his steps and sat down at the edge, legs dangling into the water. Almost absently, the Siren started stroking the calf and leaned its head against Harry's left knee.

"I don't usually mind. Power was always more important than people." It looked up, though not at Harry's face, instead resting on the strange locket that still hung around Harry's neck. He'd forgotten about it in the heat of the moment. It hadn't given off any magic anymore. He allowed pale claws to reach up and tap against the metal, a clear sound ringing out. "How did you come across this?"

"An old pirate Lord gave it to me. Said it would help me find my goal."

"Meddlesome old fool," the Siren muttered.

"Is it yours?''

"As much as its bearer," came the answer, accompanied by a mysterious smile. "But you are right, you should head back. Here." The creature closed its eyes, crystals above them rattling as power filled the room. The Siren waved its hand and released a series of unearthly tones. As the music died down, Harry realised that he was clad in a replica of his old clothes, only cleaner and dry. Well, dry until his knees, as half of his legs were still in the pool. He withdrew, noting that his new boots had buckles in the shape of eels.

"That was impressive."

"I am impressive," came the haughty reply. With a slithering sound, it sank back into the water. "We'll meet again, no doubt. If you are waiting for my followers, it'll take five more days until they arrive. A word of advice if you don't wish to lose any of your crew till then, Captain: in the meantime, they best wait at the ship and don't stray too close to the ocean itself."

"Why, are there sharks around here?"

His honest question elicited a laugh. "Any sharks that might have once wandered these waters have long since fled. No… but I haven't eaten anything but fish for two weeks and hardly anyone can catch my attention long enough for me to not consider them more than prey."

Harry faltered, reminded of the drawings in the other cave. Well, it's not as if it came as a shock. If one might believe the old tales, humans were the primary source of food for many magical beings off shore. For his own sanity, he decided not to comment on it. "I'll ensure they'll keep on the ship."

"You are of course welcome to join me whenever you feel the urge to." With a last, lecherous smirk, the Siren disappeared from view.


Hope you enjoyed this smutty monsterfucker fic :P
There are still two more chapters to come, although I am not entirely sure when I can write and upload those. (no fixed update schedule like with IWS, sorry)

In case you would like to hear the Siren's song (or just judge my singing voice, lol) I uploaded it on my tumblr account: Hikarimeroperiddle. A direct link can be found in the AN on Archive of our own (again, FFN does not allow links). The song has original text to an adapted melody of 'Softly I sing' by the artist Hania Lee.
(somehow I'm not entirely sure why I am so invested in such a smut fic that I both drew art and made songs, but here we are).
Any comments are appreciated :)

Please read and review!
xx GeMerope