"Hrrrmmmm…" the great dragon's murmur filled the ruined cavern that had once been the dwarven nations throne room with a strange echo, like an enormous cat purring. The forked tongue, dripping with noxious fluids slid slowly up Thranduil's arm, towards his face. "Exquisite indeed."
A flash of elven steel and a lightning quick strike; a hiss of pain escaped Smaug as he quickly snapped his tongue back. But not quick enough; a small sliver of flesh and some blood on the floor proved the elven blade true.
"Enough of that." Thranduil stood still on the vastness of the gold horde, pale silver amongst the gold. "I come here as one king to another."
"A king, you say?" Tossing back his head, Smaug roared his laughter; stones fell from the ceiling and the mountain shook. "Do you as well claim to be King under the Mountain? Do you also come to take vengeance on this dead folks?" he slid his wounded tongue around his mouth. It was no more than a tiny scratch, but it had been a long time since anything or anyone hurt him.
"I have no interest in dead dwarves. And I have a kingdom already with no use for another." Thranduil looked around on the dwarven treasures, more gems and jewels and wondrous items than he could have ever dreamt. His eyes gleamed. "There is indeed something else I desire from you, King under the Mountain."
"Oh?" Smaug leaned forward, his huge head so close to the elven king's that silver haired flew in the warm air. "So you have no love for dwarves or men, then. What do you love, elven king? Diamonds and jewels? Have you come like a thief in the night to steal my treasures?"
"I have announced my presence and stand before you, King under the Mountain. I am no thief." Thranduil didn't back away from the ancient evil. If anything the shining desire in his own eyes were an equal to the great serpent. "I have come for an honest bargain."
"Ha! And what would you have to offer me, one King to another?" Smaug huffed, his deceptingly huge bulk shuffling fluidly as smoke. His long neck twisted as he moved around the elven king, snuffing and snarling. "I smell trees on you, and starlight and a son and merriment and naught else. Nothing to interest me, the King under the Mountain." He licked his powerful jaws, please with the title.
For a fraction of a second Thranduil stiffened but his cold composed control soon returned.
"I offer you a gem such as you have never owned. I offer you a living jewel. I offer you…this." And with a simple motion he released the clasp holding his robes and stood before the dragon, as naked as the blade still in his hand.
Smaug hissed, rearing up in surprise and sudden delight. Greedy eyes ravished the pale body in front of him and he leaned forward once more, this time breathing in the more personal scent of the elven king whose shining eyes never left the dragon.
Again Smaug roared with laughter, tossing his great head skyward.
"So!" Cruel eyes burned down on the pale figure. "This is what it takes to buy an elven king, a king under the Trees? A handful of gold and jewels or enough to please the greediest of hearts? To become a consort to the King under the Mountain?"
"No." Ignoring the dragon, Thranduil turned his back to Smaug and gracefully walked up to the top of the pile of gold, silver hair swinging. Every now and then he crouched to pick up some pieces of jewelry or gems; some he hung around his neck or arms or fingers, others he tossed carelessly away. On the top of the pile he stopped, now almost face to face with the fire dragon. In the dreary light of the cavern he shone like the Arkenstone, but with the living light that belonged to all eldar. Fascinated Smaug considered him, unafraid and unclad but for the jewels and the sword; he was unlike anything the dragon had ever seen before. Dwarves and Men he'd seen and killed aplenty, but this was something new. A living treasure. "It would require something more than even this immeasurable treasure to win me, King under the Mountain."
When he leaned forward this time, Smaug didn't stop at the mere presence of the elven king. Instead he pushed the scaly maw against the strong chest and groin, the long tongue once more sliding over the strong body, but this time the sword didn't sing to stop it. Teeth as big as Thranduil was tall shone white in the dark jaws.
"What do I care what you desire, little elf?" He growled and in the deep maw, a tiny fiery light was lit. "What do you think you can tempt me with? Even with a treasure such as this - " he snuffed almost disdainful over the lithe elven body "- what would I do with it?"
Strong hands touched the scaled lips. Elven smooth features pressed against the dragon.
"What do you do with all your treasure, King under the Mountain?" The words were barely a whisper, barely a mumble. "You lay with it. You sleep with it."
Skilled elven hands worked over the dragon's head, down along the huge neck. The dark scales were coarse and yet more supple and strong than any mithril chainmail could ever be; living armor that it would take a siege engine to break.
Or skilled elven hands to please.
Smaug had never known such an intense pleasure, and yet the little creature was only caressing his neck and head. A sparkling gem, a living treasure to bestow upon him such delight. Touch was not something a dragon was familiar with - unless it was the touch of metals, sharp swords or shining gold - but he could delight in this. Oh yes, he could.
Like a great serpent basking in warm sunlight, Smaug laid his head down on the pile of gold by the elven king's feet, rolling his neck to grant the elf easier access to the comparatively more sensitive areas around his mouth and eyes and nostrils, the - to a dragon - tender skin under his maw. The cruel eyes shut in delight, but the mind behind them was ever watchful. In this elf he felt a kindred spirit; a creature of smaller statue than a dragon perhaps, but one who's desire for beauty and jewels were almost his equal. One who cared not for the lives of dwarves or men.
"And what would you have from me, in return, fair little treasure?" He mumbled, his eye opening a slit. "The Arkenstone? The throne of the dwarves? All the treasure and jewels your greedy cold heart might desire?"
He rolled over and Thranduil straddled his neck, strong legs slung wide to accompany the bulk. So puny and yet so cold and radiant and perfect. Like a star in his grasp.
"What would I do with the seven kingdoms of the Dwarves? They can keep the crude diamond for all that I care."
The elven king leaned down to kiss dark scales. The touch shouldn't even have been noticeable through the tough hide, and yet Smaug shuddered with delight. A heat that was not dragon fire started to build in his body.
The dragon's chest was too wide to straddle so Thranduil had to pull his legs up, crawling down the reptile body with slow, torturous delight. A claw as tall and sharp as the spear of Gil-Galad raked down his back, sharp enough to draw blood but tender enough to do no more than that. A hiss escaped the king and his eyes glowed. Smaug's cruel eyes glowed in the dark as he leaned his long sinuous neck forward to once more fix the elf in his stare. On his chest, Thranduil glowed like an ornament, like a silmarillion.
"What does it take to win you, King under the Trees?" The dragon growled, long claws flexing around the naked lithe body.
"I desire only one thing, King of Dragons." Something shone in Thranduil's hands, something Smaug had forgotten. "Your heart."
And with that he drove the sword into the gap of the one lost scale in the armor - the scale loosened by Men, found by a Hobbit, exploited by an Elf - the forged steel sinking into noxious flesh as deep as the elven king could drive it, as deep as his arms could reach.
Smaug roared in agony and fury, rolling like a swamp lizard to crush the betrayer but Thranduil was already moving, fluttering as light as a leaf over the dragon's death throes. He didn't stop until he was across the hall, far out of reach from the dying usurper. There he stopped, and looked on with cold eyes as the dragon's struggles got weaker until they died out altogether.
"Lizard," he spat. "No one threatens my son."
Epilogue:
"I suppose you did that...well enough. King Thranduil." Thorin muttered as he beheld the huge carcass.
"I did." Once more clad - although he had not removed the jewels - Thranduil stared down at the thirteen gaping dwarves and the delighted hobbit. "And now I will claim my reward."
"Yes. Balin!" Looking uncharacteristically grumpy for someone who had just been had his kingdom returned to him, Thorin turned to the old dwarf.
"Here you go, King Thranduil." Balin held forward the bejeweled box. "The silver and starlight jewles that were promised to you long ago."
Thranduil stared at the box.
"And?" He said coldly.
"And our apologize." The sound of Thorin's molars gnashing was almost as loud as the dragon's roar had been.
"And?" Thranduil crossed his arms over his chest. Balin sighed, put down the box and found the very long contract the dwarves had been forced to sign. He started reading from the top.
"And one tenth of the treasure to be delivered to Mirkwood as soon as it is safe to do so. The part of the treasure will be chosen by the King under the Woods himself from all the dwarven treasure, baring the Arkenstone, of course." Balin mumbled a little. "But I really think there should be some hazard pay for us as well. We had to sit on your son to keep him from barge in here at the most inappropriate moments."
Thranduil ignored him and kept staring at Thorin who stood with his shoulders bunched up and his hands fisted, looking like someone had just stolen his treasures, not returned them.
"And?" The elven King hissed, and held up a hand to stay Balin. "No. He should say it."
"And." Thorin looked in dire risk of breaking a blood vessel in his brain. "Every year. On this...glorious day. We will hold a feast. To celebrate...the glory and beauty of Elves."
"Just so." Finally accepting the jeweled box, Thranduil turned to leave. He reached down a hand to help up his son who looked slightly dazzled and frayed after having seen his father seduce a dragon and then being sat on by thirteen dwarves and one hobbit. Leaving the new King under the Mountain to seeth, the two elves started towards the exit, but Balin caught up with them.
"That really was a fine display of cunning, King Thranduil." the old dwarf said. "Perhaps I could interest you in a similar bargain? You see, there is this balrog in Moria..."
Legolas choked and stumbled in shock, but Thranduil kept walking.
"Absolutley not. Do you have any idea how much singed hair smells?"