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The restoration of Erebor had been a feat of legendary proportions, but the subtle transformation within its walls was perhaps more remarkable than the gold and silver being pulled from the deep. Three years had passed since the dragon was slain and the line of Durin restored. The mountain was humming with life, the clatter of hammers, and the rich smell of roasting meats and coal fire.
At the heart of it all sat Bilbo Baggins. He had stayed, much to the initial surprise of the Shire and the eternal delight of the King Under the Mountain. He was no longer just a "burglar" or a "friend"; he was the Consort-elect, though the official titles often felt too heavy for a Hobbit who preferred a comfortable armchair to a throne.
However, the mountain was doing something to Bilbo. Or rather, Bilbo’s nature was doing something to him.
The first things to change were the mannerisms. It began with the language. Hobbits, being a people of the earth, had always been mimicries of their surroundings, but Bilbo had lived his entire life in a bubble of Shire-talk. In the vast, echoey halls of Erebor, his soft Westron began to thicken.
It started small. Bilbo would trip over a loose stone in the hallway and, instead of a "Bother!" or a "Dear me!", a sharp, guttural Khuzdul curse would fly from his lips. He didn't always know exactly what he was saying,he was going purely off the "vibe" of the swear,but the impact was significant.
Thorin was the first to fall victim to this. They were in the royal counting room, Thorin brooding over a ledger, when Bilbo dropped his fountain pen.
"Oh, shathûr!" Bilbo huffed, bending down to retrieve it.
Thorin’s quill snapped in his hand. He stared at Bilbo, his brain seemingly short-circuiting. To hear those harsh, sacred sounds coming from the mouth of his soft, auburn-haired Hobbit was like seeing a songbird suddenly roar like a lion.
"Bilbo," Thorin rasped, his voice thick. "Do you know what you just said?"
"I expect I said 'bother it,' or something to that effect," Bilbo replied airily, wiping the ink from his fingers. "Balin says it when he drops his spectacles. It has a very satisfying 'thud' to the sound, don't you think?"
It didn't stop at swears. Bilbo began to invoke the Maker. "Oh, my Mahal!" he would cry when he saw the state of Kíli’s laundry, or "Thank Mahal for that," when a fresh shipment of pipeweed arrived from the south. To a Dwarf, Mahal was a deeply private, racial deity,the Smith who shaped them from stone. For anyone else to use the name would normally be a grave insult, a closed social practice guarded with teeth and steel.
But as the Dwarves watched Bilbo bustle about, wearing a miniature set of mithril-linked mail and a heavy fur-lined coat, they found they didn't mind. In fact, they loved it. Bilbo belonged to the mountain, and if the mountain belonged to Mahal, then so did the Hobbit.
It was the physical changes that finally began to worry the Company. Hobbits were a race of profound adaptability, a trait buried deep in their genetics from the days before they crossed the Misty Mountains. In the Shire, surrounded only by other Hobbits, they stayed "Hobbit-ish." But Bilbo was the first of his kind in an age to live deep within the stone, surrounded by the density and magic of the Dwarves.
His body was listening to the mountain.
His hair, once fine and silk-soft, began to change. The auburn curls became denser, coarser, and grew with a ferocious speed that required a heavy silver comb. It started to look less like Hobbit-hair and more like the thick, lustrous manes of the Dwarven lords. He even began to sprout the faintest, softest hint of whiskers along his jawline,not a full beard, but a "Dwarven shadow" that he kept meticulously groomed.
Then there were his eyes. The brownish-gold irises seemed to sharpen, the pupils dilating more easily in the low light of the deep tunnels. He stopped carrying a candle when he went to the kitchens at night. He could see the grain of the stone and the path ahead as clearly as if it were midday in the Shire.
His physique, too, was responding to the labor and the environment. While he kept his comfortable Hobbit chubbiness,the essential "padding" that Thorin found so distracting,beneath it lay a new layer of dense, hard muscle. He was broader in the shoulder, his chest deeper. Even his height shifted; he gained nearly three inches, bringing him closer to the eye level of his companions.
Most strangely, the small, vestigial tail he had always hidden beneath his trousers,a rare but persistent trait in some Tookish lines,had shortened significantly, tucking closer to his spine as his center of gravity shifted to match the sturdy, grounded gait of a Dwarf.
His appetite, perhaps the most sacred part of being a Hobbit, adapted last. He no longer felt the desperate need for seven meals. The density of Dwarven cram and the heavy, mineral-rich stews of the mountain sustained him longer. He settled into four hearty meals a day, which was still a scandal by Dwarf standards (who usually ate two), but a mark of his transformation.
"He's... he's different, isn't he?" Fíli whispered one evening, watching Bilbo lift a heavy iron pot of stew with a single hand,a task that would have taken him two hands and a stool three years ago.
"He's getting sturdier," Kíli agreed, his brow furrowed. "And have you seen his eyes? They glowed green in the shadow of the pantry earlier. It gave me quite a turn."
Thorin, sitting nearby, said nothing. He was too busy watching the way Bilbo’s denser auburn curls caught the firelight. Every time Bilbo laughed,a sound that was becoming deeper and more boisterous,Thorin felt a jolt of possessive, soul-deep love. He didn't care if Bilbo was turning into a Dwarf; he only cared that Bilbo was his.
However, the Dwarves were traditionalists. They feared the Hobbit might be falling under a "Mountain Sickness" of a different kind,a physical corruption of the stone.
When Gandalf the Grey finally made his way back to Erebor for a visit, he was met at the gate not by a formal guard, but by a frantic Balin and a worried Dwalin.
"Wizard! You must look at the lad," Dwalin grunted, gesturing vaguely toward the royal gardens. "He's changing. He's speaking the tongue, he's invocation the Smith, and he's... well, he's getting thick."
Gandalf found Bilbo in a small courtyard, sunlight filtering down through a clever shaft in the ceiling. Bilbo was wearing a tunic of dark blue wool with gold embroidery, his feet,still hairy, but the hair was now thicker and darker,tucked into a pair of sturdy, open-toed sandals.
"Bilbo Baggins!" Gandalf boomed, his eyes twinkling. "You look remarkably... substantial."
Bilbo beamed, wiping his hands on a cloth. "Gandalf! Just in time for tea. Or is it luncheon? I’ve lost track a bit, the Mountain has such a wonderful rhythm to it."
After a long afternoon of observation, Gandalf sat with the Company in the private royal solar. Thorin sat at the head, Bilbo at his side, leaning comfortably against the King’s fur-lined shoulder.
"There is no need for alarm," Gandalf said, leaning back and blowing a smoke ring in the shape of a mountain goat. "You are simply witnessing a biological marvel that hasn't been seen in these lands for centuries."
"Explain," Thorin commanded, his hand resting protectively on Bilbo’s knee.
"Hobbits," Gandalf began, "are a race of incredible social and physical malleability. In the Shire, they stay as they are because the environment is static. But a Hobbit’s body is designed to harmonize with its neighbors. It is a survival mechanism from the Wandering Days."
He gestured toward Bilbo. "Bilbo has lived with Dwarves, eaten Dwarven food, and breathed the air of the forge for three years. His body is simply 'correcting' itself to fit his social reality. He is becoming more Dwarven because his heart has decided this is where he belongs."
The Dwarves exchanged looks of pure amazement.
"Is that why the Hobbits of Bree are different?" Balin asked, his scholarly mind spinning.
"Precisely," Gandalf nodded. "The Bree-hobbits live among Men. Consequently, they are taller, their frames are more spindly, and they are far more likely to wear boots and shoes. They have adapted to the 'Mannish' standard. Even the Old Bullroarer, who was said to be so tall he could ride a horse,he spent a great deal of time in the company of Elves in his youth. He took on their height and some of their grace."
Bilbo looked down at his own hands, noticing for the first time how the skin was slightly tougher, the knuckles more pronounced. "Well," he mused, a small smile playing on his lips. "I did wonder why my waistcoats were getting tight in the shoulders rather than the belly."
For Thorin, this explanation was both a relief and a dangerous stimulant. Knowing that Bilbo was physically changing because of his love for the Dwarves,and specifically for Thorin,was almost more than the King’s heart could handle.
A few days later, they were walking through a newly excavated gallery. The air was cool and the shadows were deep.
"Look at this vein, Thorin," Bilbo said, his voice dropping into a low, appreciative hum. He reached out and touched the raw ore, his eyes flashing with that new, golden-edged clarity. "It’s beautiful. By the Smith’s beard, I’ve never seen a strike so clean."
Thorin stopped in his tracks. By the Smith’s beard. Bilbo turned, a playful, slightly mischievous look in his eyes,a look that was very "Took," but with a new, rugged edge. "What? Is there something on my face?"
"No," Thorin choked out. "I just... you are..."
Bilbo stepped closer, his new height making the gap between them much smaller. He reached up, his fingers,now calloused from gardening and the occasional smithing lesson,tracing the line of Thorin’s jaw.
"I feel at home here, Thorin," Bilbo whispered, his voice vibrating with a grounded, Dwarven resonance. "My body seems to agree."
Thorin leaned down, his forehead resting against Bilbo’s. The Hobbit smelled like lavender and ozone, like pipeweed and deep-earth minerals. It was the most intoxicating scent in the world.
"If the Mountain wishes to claim you as its own," Thorin rumbled, his arms winding around Bilbo’s broadened waist, "I shall not argue. As long as you remain mine."
Bilbo laughed, and the sound was like silver hammers on an anvil. "Oh, I think it’s a bit late for that, you old stone-crusher. I’m quite certain Mahal has already signed the papers."
As the months turned into another year, Bilbo’s transformation reached a plateau. He remained a Hobbit, undeniably,he still loved his tea, his books, and his gossip,but he was a Hobbit of the Mountain.
The people of Dale and the Elves of Mirkwood would visit and marvel at the "Dwarven Hobbit." He became a symbol of the Reclaimed Mountain,sturdy, resilient, and unbreakable. He began to wear his auburn hair in a single, thick braid down his back, fastened with a silver clasp given to him by Glóin.
He never noticed the stares or the whispers. He was too busy living. He would spend his mornings in the gardens, his increased strength allowing him to move boulders that once required a team of ponies. His afternoons were spent in the archives with Balin, his night-vision allowing him to read the oldest, faintest scrolls in the dimmest corners.
And his evenings? His evenings were spent with Thorin.
They would sit by the fire in the royal apartments, Bilbo tucked under Thorin’s arm. Bilbo would recount the day’s events, occasionally punctuating his sentences with a Khuzdul word that made Thorin’s heart skip a beat.
"You know, Thorin," Bilbo said one night, looking at a small, framed map of the Shire he still kept on the wall. "I think the Gaffer would barely recognize me. He’d probably think I was some strange, beardless Dwarf who’d stolen his neighbor’s face."
Thorin squeezed him tighter, his chin resting on the crown of Bilbo’s thick, curly head. "Then the Gaffer is a fool. For I have never seen a face more beautiful, nor a soul more suited to these halls."
Bilbo hummed, a deep, contented sound that resonated in his chest. "Oh, hush. You’re just saying that because I’ve started swearing like Dwalin."
"That," Thorin admitted, his voice a low growl of affection, "does help."
Bilbo laughed, and as he drifted off to sleep in the heart of the mountain, his body continued its quiet, magical work. He was a Hobbit who had found his pack, his mate, and his home. The Shire was a lovely memory, but Erebor was his reality. He was the Burglar who had stolen a King’s heart, and in return, the Mountain had given him a body strong enough to hold it.
The transformation was complete, not because of magic or curses, but because of the simple, undeniable fact that Bilbo Baggins was a creature of love. And in the House of Durin, love was as solid and enduring as the stone itself.