"It truly is that hard for you, then."

Smaug cracked open an eye. Dale was in the process of being restored, and the people of Laketown had finally come to claim what he had promised them: ten gold coins per person, more than many of them saw in their entire lives, as recompense for destroying their homes and lives. The dragon himself was well away from the hoard while they claimed it, knowing that if it happened before his own eyes he would not allow it, but he was confident that the dwarves would only allow them to take what was due to them.

Instead, he lay curled on a high platform overlooking the throne room. He had heard his visitors approaching, but waited until they spoke to acknowledge them. "It is," he rumbled to the dwarf prince, "You felt a shadow of it fall on your heart when I was shot."

"Sorry about that," said Bard.

"I was trying to murder you at the time; it's fine." He turned back to the prince, soon to be king. "But for you, that was only a shadow, and so you were able to throw it off. You were not made by Darkness, out of Fire and Greed. The goldlust does not twine round your bones and fill your heart and mind until there is nothing left."

"You gave up the Arkenstone easily enough," Gandalf pointed out.

Smaug huffed. "That is because it was easy. That stone is cursed, and it is not gold."

"'Cursed?!'" Thorin cried, "What do you mean, 'cursed?!'"

"Perhaps the stone itself was not cursed once, but it is bound up in one." The dragon looked away, and they all followed his gaze to where the Arkenstone had been set back in the repaired throne of Erebor. "Tell me, Thorin-King: what do you know of the Silmarils?"

He frowned and shook his head. "I have heard the term, but I know nothing about them."

"My egg was not yet laid when they vanished from Middle-earth, and though I read much about them in the Old World, it is not the same. Gandalf, will you tell the tale?"

The wizard sat down on a bench and pulled out his pipe. "To tell the story in its entirety would take a long time indeed, so I shall summarize as best I can.

"Back during the First Age of Arda, before the Years of the Sun, Valinor was lit by Two Trees, Telperion and Laurelin, and Middle-earth lay in darkness. It was during this time that the elves were discovered by the Valar and lead into the West to live in the light of the trees. To two of these was born a son who came to be called Fëanor for his fiery spirit. The works of his hands were great indeed, but the greatest of all were the Silmarils, three gems of indescribable beauty filled with the light and essence of the Two Trees.

"For a long time, Fëanor wore them set into a crown so all could see them and marvel at his work, but in those days, Morgoth was at work, spreading deceit amongst the elves. He grew to distrust all, even the Valar, and hid the Silmarils away from everyone save his father and sons.

"Eventually, the truth came out, and Morgoth fled Valinor, returning in secret with the Spider Ungoliant. Together they destroyed the trees and stole the Silmarils, slaying many elves in the process, including Fëanor's father, Finwë. He and his sons swore an oath upon the name of Illúvatar that they would never allow any to withhold a Silmaril from them, and to pursue with violence any who tried, whatever their race or reason.

"One Silmaril was recovered by Beren and Lúthien, the lovers of legend in the First Age. Their granddaughter's husband, Eärendil the Mariner, wears it now, and with it traverses the sky in his ship Vingilótë, guarding the Sun and Moon.

"The other Silmarils were reclaimed by the Valar during the War of Wrath, and stolen again by Maedhros and Maglor, the last of Fëanor's sons. But the Silmarils rejected their claim of ownership, and burned them both. Maedhros threw himself together with the Silmaril into a fiery pit. Maglor threw his into the deeps of the sea, so far that even Ulmo, Lord of the Deeps, could not find it, and then he passed out of all knowledge."

The five sat in silence for several minutes before Thorin turned to Smaug. "And you believed that the Arkenstone is one of these Silmarils? The one thrown into the fire?"

"It was a popular belief in the Old World. But it could be either of them, really, if indeed it is a Silmaril." The dragon hummed. "I admit, I do not recall much of the Earth Sciences of the Old World, but I know there is a way." His eyes narrowed. "It had something to do with the crust of the earth, and a deep trench, and earthquakes."

"Sub… subd… Subduction!"

"That's it!" The dragon grinned at the hobbit, then turned back to the others. "The world – the Old World, at least – sits atop the core of the earth like rafts on water, but they're very large and very close together, so close that there are almost no gaps to see what's beneath. The liquid rock underneath has… currents like the ocean, like rivers, and it makes the earth-rafts move, sometimes grinding past one another in opposite directions – that's what causes earthquakes.

"But there are places, usually under oceans, where one earth-raft slips under another and gets pulled down. They were called subduction zones."

"Let me stop you for a second," said Bard, "I thought you didn't remember much about Earth Science. Why do you even know all this anyway?"

"Do you remember when Sherlock came out of retirement for one last case? The one in… far in the west, across the ocean?"

"America, I think. California? And yeah, I remember."

"That's it. America. Well, he solved the case, and we stayed there a little longer on holiday. There was a minor earthquake while we were there. He was endlessly fascinated, of course, but that's about the limit of his knowledge. He probably can't even name the different types of rock."

"There are different types of rock?"

"And there you have it." Bilbo turned back to the dragon. "Please, continue."

Smaug narrowed his eyes at the hobbit, then said, "Gandalf said that the Silmaril was thrown so deep that not even the Lord of the Deeps could find it. In the Old World, the deepest point on Earth was a subduction zone eleven kilometers under the surface of the sea – a little over three times the height of the Lonely Mountain."

Thorin – and Gandalf, too – looked amazed at that. Even Bard and Bilbo swallowed, wide-eyed.

Smaug paused for a second, searching his memory, then said, "To my admittedly limited knowledge, the floor of the Belegaer has never been mapped. It's possible there could be one such subduction zone there, and the Silmaril was caught in it and pulled under into one of the currents of the core, and then pushed up into Erebor during a volcanic eruption. You said so yourself, Thorin-King: the Lonely Mountain used to be a volcano."

"I did," the dwarf agreed, nodding, "But whatever the stone may really be, this curse you say is on it… is it the source of our misfortune? A dragon attack…"

"Gold-sickness," added Bilbo.

"Armies of orcs," Smaug hummed, "and I cannot say for sure. It may very well be. It was only by chance that I learned of the Treasure Under the Mountain in the first place, and while the goldlust is in my blood, it was also present here before ever I arrived."

Thorin frowned at that. "I've no wish to fall prey to it again. If it is, what can be done? What happened to the Arkenstone in those books and magic pictures of yours?"

Bilbo blinked, then shook his head. "I can't remember."

"Don't look at me," said Bard, "I never read the books, and I didn't see the last one."

"'Last one?'"

"There were three magic pictures made," Bilbo explained to the dwarf and wizard, "'Movies,' they were called, because they moved. The first one told the tale of everything from the beginning of the Quest in my home to our arrival on the Carrock. The second one dealt with everything from there to Smaug leaving Erebor to attack Laketown, and the third one was everything from there to – what originally was your death and funeral, and my return home. Should be fairly obvious, but that very last bit hasn't happened. Smaug? Do you remember what was done with the stone?"

The dragon's eyes were narrowed, the very tips of his forked tongue between his teeth. At last, he said, "In the original tale, you died, Thorin-King, and the Arkenstone was laid to rest with you in your tomb. So far as any other writings told, there it remained, and troubled no one."

"Returned to the earth…" The dwarf pursed his lips, then nodded. "That seems right. But I yet live and have no tomb, and those of my father and grandfather stand empty. Let it be with them, instead, when they gave so much trying to reclaim it."

He had Gandalf confirm the dragon's words before doing anything, of course, but a few words of High Elvish and a sharp rap from the wizard's staff were sufficient to prove Smaug right – the Arkenstone was indeed a Silmaril, though which of the missing could not be known. And it was indeed cursed – invisible to most but revealed by the wizard's magic, even though it had been hallowed by Varda, a web of sickly black magic was threaded around it, too powerful to have been laid in by anyone but Morgoth himself, too powerful for any but the Valar to remove.

It was laid to rest in secret in the empty tomb of Thráin, Thorin's father, and there it remained, and troubled no one.