Written for this prompt: 'When they're escaping from the goblin tunnels, everyone makes it out...except for Fíli. Pushing his brother ahead, he falls behind. Kíli has to be dragged away. Only later do they realize that the Goblin King traded the one captive that didn't escape to avoid Azog's wrath when he didn't have Thorin's head after all.

Azog is only too happy to cast his broken prize at Thorin's feet when he finally catches up to the company.'

The Price of Brotherhood (1/8)

By Swiss

They run, and every muscle in Kíli's body was screaming. His sword felt like dead iron in his hands. He plunged it into another body that came shrieking toward his face, felt the pull of flesh as it bit deep, and then he was past – careening – their company yanked forward by their own momentum. Running and fighting, the goblins lunging around them as they barreled head-first down and down the wooden bridges of the Goblin domain, they followed Gandalf's grey back as though he were an anchor and the rest of them were fastened to him like a chain.

Kíli gasped, tasting iron. He felt the brush of his uncle's fur mantle against his shoulder, a reassuring nearness. At his back was the shouting of his dwarven kin and companions. He heard Bifur's hoarse, wild roar; the shrill grate of Glóin's axe as it grazed stone. Ori, inexperienced and terrified, cried out as he fought with a sound close to a wail, but his brothers were beside him, a whirl of bola chains and heavy blade.

His eyes carried past them, desperately seeking his own brother, but he stumbled over a fresh corpse, tripped, and barely kept his feet as their wild flight continued ever onward. A flash of elvish steel just prevented a goblin spear from penetrating his skull, and he heard his uncle bark, "Kíli! Eyes to front!" before he had his own weapon back to bear in the hellish mêlée.

"The bridge! Cut it!" he heard Gandalf bellow, and then the world beneath him lost gravity.

The wooden planks, held together by moldy rope and filth, swung free as a body, and the dwarves screamed as they were propelled through the air. Then the edge slammed into a bank of stone, and they hurled themselves onto the path. Kíli felt Thorin's hand, steely around his arm, and swung his head back in time to see the bridge collapsing sideways, splintering to fragments as it fell into the impossible void of the deeper caverns.

His pulse hammered as he caught the flash of fair hair at the extreme end of the group, and for a moment he was back on the mountain pass on the knees of the stone giant, watching as a chasm opened between him and his brother in a deluge of rain. A scream burned in his throat – but then Fíli leapt into mid air just as the last board disappeared from under his feet, and cousins Bifur and Bofur pulled him clear. Lightheaded, Kíli raced on, breathless after that near fatal separation.

He wanted nothing more than to stop and be carried back to his brother's side. Since they were children and took their training in the Blue Mountains, this was the manner in which they fought best. And even before then, before they had been taken in and fostered by Thorin, Fíli had been his bulwark of protection, the one wall to which he could always put his back. Without him, Kíli felt exposed, and in terror for his brother's life. However, in this case their own company was between them, and he would not endanger them by so foolish an action.

The heat of the battle was intensifying. Swarms of foul goblins surged from the crevices, dropping from above or climbing from the pits below, their claws letting them fasten to the rock and leap at the company from every angle. Thousands of them, in the heart of their own territory. Even as he wearily lifted his blade, now glistening with sticky black ichor, Kíli knew they would soon be overwhelmed. Then, with a huge cry, the Goblin King heaved himself up before them, laughing and swinging his huge mace.

"Where will you go now, Thorin, king?" the Great Goblin taunted, his massive bulk a wall of flesh, his followers around him like writhing vermin. "Surrender now, and I'll only torture you. The rest I will show mercy. I'll crush their skulls with my own hand – sweet night. They won't even be alive when my pretties start to eat them."

Thorin struck out in response, his face thunderous, a black mask of defiance. The Great Goblin parried the blade that he had so fearfully called "the Biter", but his foot made the entire bridge creak as he stumbled back, and in that moment the wizard's staff came down.

A huge sound of rotting wood splintering away, and slivers of debris flew by Kíli's face, scraping his cheeks and brow. His arms drew up to shield his eyes, but once more gravity had abandoned them, and he felt himself lose footing as the bridge they had been standing on scraped like a massive sled down the edges of the cavern, down and down and down, Óin screaming in his ear, until with a huge jarring impact, they slammed into the ground and the tiers of their unlikely vehicle collapsed on top of them.

Compressed by the wreckage and by the weight of his brethren, Kíli lay groaning. "Fíli," he wheezed, struggling to free his pinioned arms, and felt almost faint with relief when he saw his brother below, his blue eyes dazed yet still keen. He clasped Kíli by the hand and hauled him free, and for a moment they were side by side, leaning on one another as they gasped for air. Kíli let his forehead fall against Fíli's shoulder.

"Are you alright?" his brother asked. The fur bordering the collar of his tunic was wetted with blood – His own, or an orcs – but his tranquil, steady eyes were fixed on Kíli.

Kíli clasped his brother's shoulder reassuringly, barely swaying as he forced himself upright. "I'm fine. Winded only, and bruised." His face faltered somewhat, and he admitted, "Afraid, when the bridge came free and you were –"

A cheeky grin crept onto Fíli's face, twitching around the edges of his moustache. "Where you not occupied enough with the goblins to waste your time staring back at me? Keep your attention on the enemy, little brother. I can look out for myself."

Chagrined, Kíli ducked his head. He had heard admonitions of that sort before. Though he was the younger of the two of them, he had often been accused of being overbearing when it came to his brother. In the times before they began this quest, Balin had teased him, comparing him to a hen with only one chick. Dwalin, more raffish by far, jeered that he must think his brother a maid. Their uncle, never one to jest, had even more biting things to say about it, and more than once he had summoned Kíli in the dark before a hearth and spoken to him severely about the peril of binding himself so closely, of how little it befitted either of them as warriors, of the danger, the weakness it brought on them both.

"You do him a disservice," he had said one memorable night when, having been taken on a short trip to a village of men for trade, Kíli had perhaps made too much of an insult paid at the local tavern. "He is the elder. It is his duty to defend his own honor, and our people's. You cannot fight his battles for him."

It was true that Fíli was capable of defending himself, but Kíli knew his brother, and he simply didn't have the temper that Thorin and Kíli so strongly possessed . His was a quieter heart, and though a fearless fighter, he would endure a great deal more than Kíli was willing to permit. Moreover, that evening in town had shadows in darker times than Thorin knew. Fíli and Kíli had been born among the men of the wild, in the times before the Blue Mountains had become the new stronghold of the dwarves or Erebor, and neither loved them. Kíli had seen that dirty pig shove his brother, and –

In the end, it didn't matter what anyone said about this particular subject. Without the calm of his brother's presence, Kíli was an untamed whirlwind. Without his unspoken assurances, Kíli would be towed under by his insecurities. Without his shoulder against him at night, Kíli would not know any home. His hand clinched around Fíli's shoulder reflexively, hearing the leather creak, and his heart beat hard to feel his brother's living heat.

The pound of innumerable feet, the high-pitched squeal of the goblin hoard, echoed from the distance. The heads of the poor, battered company shot up, hearing the fresh approach. "We can't keep fighting like this!" Dori despaired, casting himself loose at last and joining Bofur in heaving Bombur to his feet.

Gandalf, clasping his staff in one hand and his sword in the other, answered, "Only daylight can save us. We must head to the Goblin-gate."

Thorin, as dirty and bruised as the rest of them, yet somehow still standing tall, strode to his side. "Show us the way," he said. Then, casting a look at his nephews, he spoke to Fíli. "Don't let him fall behind."

Fíli's grip on Kíli's arm intensified. "Never," he said, though Thorin had already passed beyond the range of hearing. There was time for him to flash a strained smile at his brother, and Kíli took heart even as he hefted his weapon once more and they set off on their final change through the twisted dark paths under the mountains.

Trusting his knowledge, the dwarf company followed behind the wizard as he parted the dark ahead with the fiercely bright Glamdring, the fuller white-blue with its own radiance. This time, Kíli refused to be parted from his brother. He and Fíli were side by side at the heels of the others, racing on, but even the combined cacophony of their heavy boots wasn't enough to cover the sound of the renewed pursuit of the goblins. Casting a glance over his shoulder, Kíli could see them swarming nearer like an oozing flood. He could smell them, a reek like a body split open by heat and torn by carrion.

He felt Fíli shove him forward. "Don't look behind!" he shouted, and Kíli applied his every remaining shred of strength to running.

"Here!" He heard Gandalf shout, and suddenly their way was checked. He saw the others stopped before a slender crack, high in the rock, and beyond it was a sight that made Kíli shut his eyes after so much time in darkness – it was pale daylight. There was a shriek as the door's guardians fell, black blood soaking into the ground. Then the dwarves climbed, pushing one another up to gain purchase on the gate of stone and force themselves through.

But the hoard behind them was coming closer. Kíli whirled alongside his brother to face them, weapons drawn. His brother's twin blades flashed out, and Kíli's own bow, which had until this time been useless in such close quarters, he now brought to bear. His whistling missiles found their meager mark, but it was a vain effort. He could not hope to hold back so many with arrows.

He heard the Goblin King's huge, echoing voice – "The gate! Shut the gate!" – and a horrible grinding filled all their ears. Gears began to move. The crack of daylight pinched, narrowing. Yet the last of the dwarf company was already disappearing through it. Knowing it was his turn, Kíli threw himself toward the wall below the door, scrapping his chin bloody as he scrabbled for purchase. He reached for his uncle's outstretched hand while Thorin bellowed for him to climb.

He could not reach. Kíli had a single moment to feel despair, but even as it flashed to life a shoulder slammed into his back, pushing him up against the rock. His boot scrapped, found purchase, and then Fíli straightened, all but throwing Kíli up into the waiting arms of his uncle. The tiny gap admitted him, and he swung around, grasping back through it, screaming his brother's name. Fíli's determined expression was on him, familiar even through the grime obscuring all their faces. With complete trust, he took a step back and made a running leap, his arms out.

Kíli caught them. He doubled over as he took Fíli's weight, the arms of another around his waist the only thing keeping him from being dragged back into the cave. The leather bracers around his brother's wrists were slick. He ground into them with all his strength, but even that was failing. He grunted, pulled, and called for help – help – from anyone who would hear. Then the gears heaved, slowly turning. The door began to close the last precious inches, and Kíli screamed, caught between the gate with his brother still below.

It was at that point that everything slowed, and the sound went out. Only a roar was left. Kíli looked down on his brother, whose fair hair tangled around his neck and face. Blood was tattooed over his temple, and his jaw was a rigid line. But when he looked up at Kíli, his mouth relaxed into the smile he was more known for. He eyes spoke with a terrible finality. Kíli shook his head violently, denying it, refusing any farewell. Yet he could do nothing when, as the goblins finally swarmed around Fíli's legs, his brother let go and let himself fall.

"NO!" Kíli screamed, his voice breaking as he was pulled back from the door. It groaned as though it were the throat of the whole mountain, and then the gate closed entirely, leaving Kíli facing a solid wall of stone.

Thorin's arms were around his waist, a voice in his ear, but Kíli threw him off. He hurled himself at the door, agony pouring out from somewhere deep in his body, pounding with his hands as he screamed his brother's name. His fingers bled, but he could not find a seam. He plied all his exhausted strength, but the mountain was unyielding. Finally, he sobbed, pressing himself against the rock. Again, he felt his uncle at his back, felt other hands pulling him away. He fought, but they mastered him. Dragging him down the last corridor toward the daylight.

They left the dark behind, and Kíli still had to be dragged to prevent him from falling back. Even as the breeze finally cooled his cheeks, and the smell of pine caressed him as they left the close, damp caverns, he was senseless. Finally they reached a clearing, and, able to go no further, the company collapsed, breathing heavily.

Kíli was all but dumped on the ground, Dwalin and Thorin over him. "Kíli." His uncle knelt, clasping his shoulders, but Kíli shoved him away. Tears carved their way freely down his face, and a keening noise echoed in his ears which he soon realized was his own voice. Fíli.

He lurched upright, ready to charge back the way they had come, but the huge, corded arms of Dwalin enfolded him. He felt the man's coarse beard against the side of his head as the rumbling voice murmured, "Down, boy. Quiet now. It's over."

No. Dimly, Kíli saw the downcast faces of his kin, saw their grief and their pity. Bofur was gasping as he wept, and Ori had his face hidden in his hands, pressed fast between his brothers on both sides. The sight of Dori and Nori's protective stance, stolidly together in spite of the strained and tumultuous relationship they sometimes shared, broke something inside of Kíli. All the strength went out of his legs.

Fíli. His own older brother, whose arms he remembered carrying him when he was too small to walk. The one who had wrestled with him. Who spoke with him through his dark moments, when his heart quailed believing he had failed to meet another of his uncle's impossible standards. Who stood beside him, with his arm around Kíli's now taller shoulders, protecting him as Dori and Nori did now. Who had thrust his shoulder beneath Kíli's boot and passed him up the rocks to safety.

Kíli's stared out at nothing, his chest like a vice. Fíli was back in that terrible mountain, with the goblins. They would kill him, or worse. Bone-breaker. A rack of teeth. They had all seen the machines being wheeled in before Gandalf arrived. What would the Goblin King do with him, when all of his other prisoners had escaped? That Fíli had died at the moment of his capture would have been his only chance for mercy.

"Gandalf," he heard Thorin say, his familiar harsh voice gone hoarse. "Is there any way?"

The wizard's grey eyes were deeply lined with grief. "I'm afraid there is not, not without sacrificing the entire company. I'm sorry, Thorin."

A hand on his neck, baring down tightly. But not the hand of his brother. Kíli bowed his head and wished to die.