Full summary:

After the Battle of Five Armies, Bilbo lies as still as death, and no earthly force will wake him. When a ghostly apparition offers Thorin the chance to recover Bilbo's absent spirit from the underworld, he accepts without hesitation.

So begins the second Quest of Thorin's lifetime.

Through half-remembered dreams and terrifying nightmares, beyond strange worlds to stranger shores, the Heirs of Durin will tirelessly, doggedly search for their burglar.

This is their task, their penance: find Bilbo, or else be condemned to wander forever more, never to return home.

Beneath carven stone and sheer rock, under the immeasurable weight of the earth suspended by Dwarven ingenuity, there lay a hobbit who would not wake.

The Lonely Mountain echoed with life, for by the steady hands of the Dwarves the kingdom of Erebor was being made anew. The great gates, flanked by its colossal guardians of stone, stood open day and night, welcoming its returning people to the comforting dark of its halls. At all hours the belly of the mountain rang with joyous voices and hammer-blows, and the deep depths glowed crimson-red with the light of blazing forge fires.

And yet, even as the Dwarves laboured, and were happy in their work (for Dwarves are always happiest when they have work), and made their pleasure at the reclamation of their home known, there were some among them who could not fully enjoy the celebrations in good conscience. For while the Dwarves of Erebor laughed and sang and feasted in their hallowed halls, setting the cavernous walls echoing with the sounds of merriment, deep, deep in the dark of the mountain, there was a room that stood silent and still, in stubborn contrast to the city that surrounded it.

At the heart of the mountain a hobbit slept, and he would not wake.

When the Battle of Five Armies had been won and Azog's forces utterly decimated, the mountainside had been left drenched in blood, its foothills obscured by the bodies of the fallen, the Desolation of Smaug made into a graveyard for Man, Elf, Dwarf and orc alike. From that bloody wreckage, a single hobbit had been recovered. It had been Bofur who had found him, half-buried under the body of a fallen elf, the hobbit's mithril shirt shining at his throat, the bright sparkle of the metal enough to catch Bofur's eye in amongst the muck and grime and horrors of the battlefield. With a great cry the dwarf had hastened to free his friend from the litter of corpses, fearful that Bilbo, too, had lost his life. But scratches and bruises aside, Bilbo had been miraculously unharmed, his life no doubt saved by his mithril shirt, his cunning and his magic ring – and likely in that order. And yet, as impervious as the chainmail had proved to be, it had not been able to Bilbo from a simple blow to the head.

With help from his cousin, Bofur had carried Bilbo to the healing tents and there, surrounded by his relieved friends, the hobbit had slept. And slept. And slept, with no sign of waking. Óin had driven himself to exhaustion by nursing Bilbo day and night, attempting every method and medication his keen mind could think of, putting his long years of experience to the test - but still Bilbo would not wake. Gandalf had sat with the old dwarf, trying magicks and medicine in equal measure – Elvish medicine, no doubt, with a touch of something else he refused to put name to – and puffing away at his pipe. But even the resourceful wizard could do nothing for his friend, and his countenance had grown graver and graver with every day that had passed.

Even the Elves had attempted to rouse the halfling, though only the once, for their visit to Bilbo's tent had been so fraught with tension that to try again would have been foolhardy in the extreme, so strained were relations between the races.

Bilbo had slept through it all without a twitch or a flicker of life, oblivious to the efforts of his friends and allies. Despondent and helpless, the Dwarves had been left with no choice but to carry Bilbo's body into the shelter of the mountain, there to set him in room of his own, hidden away from prying eyes and attended to daily by Óin.

Now, two months later, the Company of Thorin Oakenshield still found itself short one member, and their hard-won victory was blunted by grief.

For a hobbit lay at the heart of the mountain, and he would not wake.

The room had, once upon a time, been the private study of Thorin's grandmother. It was one of those odd curiosities that hardly anyone outside of the Royal Family knew about - a small, hidden-away space with only one entrance, deliberately placed in what Thorin's grandmother had considered 'the heart of the mountain'. She had been very particular about the sparseness of its decoration, insistent on bare walls and minimal architectural accents, and as a result the room was austere in the extreme - at least in comparison to the rest of the expansive Royal rooms. Thorin remembers that she would often disappear to this room for hours on end, to think and sit in silence, musing over the day's difficult decisions and upcoming trade negotiations. She had loved her family dearly, and her husband had without a doubt been her One, but she had also been the kind of dwarf who had needed a couple of hours every day on her own, away from the bustle of court life.

The rotting furniture had all been cleared away, her books returned to the family library. In their place at the very centre of the room stood a makeshift bed. On said bed, wrapped in bed sheets and with his head pillowed on a cushion, lay Bilbo Baggins.

Bilbo's skin was pale, stretched too tight over the bones of his face. Time, illness and lack of proper sustenance had carved away the plumpness of his cheeks, unearthing hard cheekbones and sharp, jutting angles. His eyes were sunken, his head of curls washed and clean but lacking the sheen of the healthy. Someone – likely Ori – had braided one side of Bilbo's hair, just in front of his ear. It surely had to have been Ori - no one else could have so cleverly combined the braids for friendship, hope and good luck, weaving them together so each style was recognisable, yet intermingled to create a new, unique braid.

By the hobbit's bedside stood a King.

Thorin had no clue as to why he came here each and every day, after the sixth bell but before the seventh that heralded the end of the work day and the beginning of the evening meal. Such uncertainty over his own inclinations annoyed Thorin almost to distraction, and caused a niggling sensation at the back of his mind. Besides, it was hardly as though Thorin's visit ever had any effect, or would in the future. Bilbo never stirred, never gave any indication as to whether his state would ever change. But day after day Thorin found himself putting aside his work, sparing a few minutes to stand by the hobbit in utter silence, to leave with his heart heavy and yet strangely satisfied by this adherence to what he assured himself was his duty. He comforted himself with the thought that, had any other member of the Company been in the same position, he would have done exactly the same thing.

Though the difference was that he and Bilbo could hardly be called friends, not when they had parted on such terrible terms.

But they had shared a Journey together, and Bilbo's friendship with the rest of the Company had been unaffected by his exile, if their constant visiting was anything to go by. Dwarven duty dictated that they honour that, although none of them knew how to solve this dilemma they found themselves in. They could not send Bilbo home to his family – Óin doubted Bilbo could survive the journey back, especially not in the onset of winter. Even if they could, who would look after him? There was no wife, no children awaiting Bilbo's return, and the hobbit had never named any close family members. They could not bury him. The thought was too horrifying to contemplate. Even now Bilbo's chest rose and fell in tiny slivers of breath, noticeable only under scrutiny.

They could do little else but continue to nurse him, though even this decision was deeply unsatisfying, for while Bilbo continued to breathe, day by day he grew thinner and weaker, in spite of all of Óin's efforts to the contrary. One day, Thorin, knew, the hobbit's body would simply stop breathing, unable to work up the strength to expand his lungs.

It was, he thought, entirely appropriate for Bilbo to be as much of a nuisance in unconsciousness as he had been awake.

It was warm here, though the walls and high ceilings were hardly of any use in the retention of heat. But the forges had been awoken in Erebor's depths, and there was not an inch of the mountain that was not suffused with warmth. Still, the hobbit might soon need furs in addition to his bed sheets, and Thorin made a mental note to bring this to Óin's attention when he saw the dwarf next. It was quiet, too, save for the flickering of the torches in their brackets. He felt cumbersome and overdressed in his courtly armour in a room so devoid of decoration, and he was glad that he was entirely alone so that no one could bear witness to his discomfort, or his awkward stance by Bilbo's bed as a result of his refusal to sit on the spare chair.

But, unbeknownst to Thorin, he was not as alone as he hoped, for over by the arched doorway stood two dwarves, hidden away in the shadows of the corridor.

'What's he doing?' whispered Kíli.

Fíli signed back at him. Shut up.

Kíli shot him a look, but raised his hands to sign, this is boring.

His brother glared at him. This was your idea, he said, his hands moving quickly and silently through the Iglishmêk. What were you expecting?

Kíli let out a small sigh, subsiding into silence once more. After a minute of watching Thorin stand beside Bilbo's bed, he said, I would have thought he'd at least talk or. He trailed off with a shrug, hands falling to his side.

We need to leave, said Fíli.

Kíli didn't bother with signing his vehement agreement. He gave a sharp nod, conveying his confusion at his Uncle's strange behaviour through his expression. Fíli rolled his eyes in response, as if to say, it's Thorin, what did you expect?

They turned to depart, their tread careful, but before they could steal away from the shelter of the shadows, Thorin suddenly turned on his heel and started to march straight for them. There was now no way that Kíli and Fíli could escape without being seen, and a hurried, flurried series of hand gestures and pointed looks followed in quick succession, the brothers trying to desperately decide on a plan of action before their Uncle discovered them.

They needn't have bothered. Thorin paused, his stride faltering, coming to stand halfway between the bed and the doorway. Kíli and Fíli froze, thinking they had been spotted, but their Uncle's attention was clearly elsewhere, and to their surprise he began to speak aloud into the deathly quiet of the room.

'I have been thinking,' he said with uncharacteristic hesitance. 'I have been considering that, perhaps…perhaps if…' he trailed off, his voice echoing faintly on the stone walls.

'And at last, you begin to understand,' said a voice.

Thorin whipped around, Orcrist out of its sheath and in his hand in the space of a heartbeat, the metal singing as it was drawn free to be held defensively in front of his body, focus entirely on the voice's source, which had issued from beyond Bilbo's bed.

And he gaped at what he saw there.

A tall figure stepped forwards, as tall as an Elf but with the blunted ears of a Man, and utterly unlike anything Thorin had seen before. Ragged, bleached-white robes trailed out behind her, dragging over the floor in a rasp. Her dress was too big by far for her starved frame, and hung loose about her hips and shoulders. Her pale, pale skin was stretched too tightly over her bones, her clavicles protruding sharply, the top of her ribcage visible under her shifting, translucent skin. Lank, long white hair fell heavily over her narrow shoulders, and her face held the suggestion of beauty, and youth, once, but gauntness had robbed any hint of it from her visage.

'Who are you?' Thorin demanded of the spectre, his grip on Orcrist never faltering.

She smiled, a bare movement of her bloodless lips, and raised a spider-like hand to gesture.

Twin cries of aggression erupted from behind Thorin. Kíli and Fíli burst forward from their hiding place, standing defensively either side of Thorin, a sword in Fíli's hand, a throwing axe in the other, Kíli with an arrow notched and at full draw.

Thorin would find time to berate them for their spying later.

The woman's hand paused in its rise, fluttered back to her side. 'Peace, heirs of Durin,' she said, her voice a bare, grating whisper.

'Step away from him!' snapped Kíli.

'The hobbit,' she said, turning to look down at Bilbo, 'has nothing to fear from me.'

She stepped forwards, towards Bilbo's bed. Thorin let out a shout and sprung forward to intercept her, but Kíli's arrow and Fíli's throwing axe got there first. Both passed through her and continued, their flights uninterrupted until they hit the far wall with a clatter.

The woman, as though nothing untoward had occurred, placed a hand on Bilbo's forehead, her touch light. Kíli immediately took another arrow from his quiver, but uncertainty now clouded his face, and he kept darting quick looks towards Thorin every few seconds.

She straightened gracefully. 'You cannot hurt me. I am unwilling to hurt you,' she said. 'It seems we are at an impasse.'

'Who are you?' said Thorin.

'It does not matter,' she said.

'What do you want?' said Fíli.

Her grey, hollow eyes flicked over to Fíli, and Thorin had to restrain from instinctively putting himself between Fíli and the apparition.

'A better question,' she said, and Thorin thought he saw something like malicious humour in her impassive expression.

'I am here to offer you a choice.'

'Whatever you are offering,' growled Thorin, 'we will have none of it.'

'Do not be so hasty, King Under the Mountain. What I offer is not a gift, freely given, or easily won. I am merely here to point the way.'

'To what?' said Fíli.

She stalked forwards, stepping around the end of the bed. The stubborn Dwarves held their ground, not budging an inch, and she came to a stop a few paces in front of them. Thorin saw that her feet were bare and mired in mud, her calves streaked with dirt.

'Your friend hovers between life and death,' she said. 'He has not yet reached Mandos' Halls, but given time, he will. But it does not have to be so.'

'What do you mean?' prompted Kíli, frowning down the length of his drawn arrow, which was still pointed unerringly at her heart.

'His spirit no longer inhabits his body. It is…elsewhere. Waiting.' She cocked her head to one side, as if listening for something only she could hear. Thick ropes of hair shifted over her shoulders at the movement, and Thorin could have sworn he heard the tendons and muscles of her thin neck creak and strain.

'This is why he does not wake. But his spirit can be…retrieved.'

Fíli gave a little shake of his head, drawn in by her whispering words in spite of himself. 'How?' he asked, the question slipping out against his will.

'Enough!' snapped Thorin, 'I say again, we do not want what you offer. Leave us in peace.'

Scorn slipped into her countenance.

'Would you leave him to die before his time?' she said, and her soft, rasping voice had taken on a hard edge. 'Are you content to sit idly by and do nothing while he wastes away? I offer you the chance to put things right. Would you refuse it so easily?'

Thorin was silent. The tip of Orcrist began to fall slowly towards the floor.

'Why help us? What reason is there to trust you?' said the King after a moment of quiet.

'I will not say. You must accept that I merely want to help, and my reasons for doing so are my own. I say again, all I can do is show you the way. The rest is up to you.' Slowly, she raised her arm to point to the door behind them.

Kíli lowered his bow and turned to look. Thorin barked out something harsh to him in Khuzdul at such foolish behaviour – his nephew should know better than to turn his back on an enemy. But Fíli was soon following, having caught sight of his brother's expression.

'Thorin,' said Fíli quietly. 'Thorin, look.'

'What is it?' said Thorin.

'The corridor…it's gone,' answered Kíli.

Thorin glared at the woman, heart full to the brim with suspicion.

'What do you mean?'

'I mean exactly that. It's not there any more.'

'Kíli, that is imposs-' said Thorin, finally turning around, and his assertions died in his throat.

The corridor, lined with torches blazing cheerfully, was gone. In its place was…nothing. Absolutely nothing. Not even the light from the room seemed to be able to penetrate the endless darkness that lay beyond the threshold. Thorin shuddered, his mind trying - and failing - to explain the disturbing emptiness.

'You will find many things along the way that are impossible,' said the spectre, interrupting their shocked silence, 'should you chose this path.'

'What…what is it?' croaked Fíli.

'It is a road, between this life and the next. Step through that door and you will find yourself in another place entirely.'

'A road to where?' said Thorin.

'To the hobbit,' said the woman simply.

Fíli let out a noisy breath, looking in askance to Thorin.

'The way is fraught with danger, and strife,' she said when Thorin said nothing. 'It will not be easy. You may fail - it is likely you will. In all the Ages of this world, only a handful of people have ever walked this path.'

'How many returned?' asked Kíli. He was still staring into the void, expression lost.

'None. Save one.'

'Who?'

'It is of little consequence,' she said with a shake of her head.

'This is not possible,' Thorin murmured, 'I have never heard of such a thing.'

'And yet, here you are. In this, Thorin, as in all else, let your heart rule your head. You know I speak the truth.'

Thorin stood, Orcrist in hand, saying nothing, and the woman hammered the last nail home on the coffin:

'I ask you, Thorin Oakenshield: how far would you go for the life of one hobbit?'

Fíli caught Kíli's eye, and saw his own distress written across his brother's face. They watched, helplessly, as the latent suspicion slipped from Thorin's expression and his chin lifted, his stance settling into something very familiar to Kíli and Fíli both: resolve.

'You must tell Balin of all that has happened here,' said Thorin. 'You must tell Dain, too. I do not know how long this path is, or if I shall ever return.'

He turned back to look over his shoulder at the woman, sheathing Orcrist.

'I cannot tell you how long it will take,' she said in answer to the unaired question, 'or if you will be successful in your task. Even if you should reach the lands where he waits, the hobbit may not want to return. You must convince him otherwise.'

Thorin gave a small nod, his eyes never once alighting on Bilbo's sleeping form. He put a one hand on each of his nephews' shoulders, looking at them in turn.

'You will stay here,' he said.

'Thorin-' began Fíli, but Thorin quelled his protests with a look.

'Erebor needs you. I need you to stay here.'

'But we could help,' said Kíli, tone sharp with anger, 'you can't do this alone.'

'I can, and I will. You will obey me in this,' he said tersely, 'it may be the last order I give to you, and you will adhere to it. Understood?'

They nodded, clearly unhappy but unable to argue with their King.

In contrast to his harsh words, Thorin pulled them both forwards into a tight, brief embrace, releasing them after a moment and turning away to face the darkness. He reached inside his heavy coat, drawing out a small bead from an inside pocket. He held it in his palm, clenching his hand into a fist so tightly that the pattern from the bead would surely be imprinted on his skin.

'If I don't return,' said Thorin, 'tell your mother what happened here. Tell her I… tell her I had no choice.'

With that he strode forwards, into the darkness. As soon as he stepped into the strange nothingness that lay beyond the door, his form vanished entirely from Kíli and Fíli's sight.

The room returned to its unsettling quiet once more. The darkness remained. Kíli glanced at where the apparition had stood watch, expecting her to have vanished altogether, her task complete. But he almost flinched when he saw her still standing by Bilbo's bed, something akin to humour crinkling the edges of her dull eyes.

Kíli looked at the threshold.

'He'll be very angry,' he said, casually.

'Furious,' agreed Fíli.

'I don't think he'll ever forgive us.'

'Probably not.'

A pause.

'Still, though,' said Kíli. 'Can't let him go alone.'

They looked at each other. A wild, reckless grin lit up Kíli's face. A small smile graced Fíli's.

Fíli looked back to where Bilbo slept on, oblivious to all that had passed.

'Sit tight, Bilbo,' he said. 'We're coming for you.'

And together, they stepped over the threshold.