Just when Sylas thought the nameless horror would swallow him whole, warmth flowed into his heart. Gandalf had wrapped him in the fire of Narya, the Ring of Fire. The crushing despair lifted, replaced by a stubborn spark of courage.

Sylas seized the moment. Clutching his staff, he chanted the strange, lilting melody Tom Bombadil had once taught him. The magic-song rose in the dark, and from it his Patronus flared into being. Like a single candle set against a swamp of shadow, the silvery light spread, driving back the clinging blackness. For a heartbeat, hope returned.

But the whispers did not cease. They grew sharper, like a thousand invisible needles pricking at his very soul. Herpo strained forward with all his strength, bearing Sylas and Gandalf, close behind the fleeing Balrog.

Once a hunter, now the hunted, the Fire Demon clawed its way ahead, carving a path of escape through the suffocating dark. In that moment, Sylas realized the demon itself was their shield: its terror at what pursued them opened the way.

Behind them, the nameless things pressed on, an unseen gaze, ancient and merciless, fastening upon them as prey.

The flight seemed endless. Time blurred into an eternity of darkness, fear, and pursuit. Then, light. At last, a faint glow appeared at the tunnel's end. Like arrows loosed from a bow, the Balrog, the basilisk, and their riders hurtled toward it.

They burst from the blackness into a passage cut by dwarven hands. Stone steps, carved walls, familiar signs of Khazad-dûm's craft. The suffocating presence behind them lingered for a moment, then ebbed away into the abyss.

Sylas collapsed against Herpo's scaled neck, drenched and trembling. He could not tell whether the dampness on his skin was sweat or the freezing waters of the abyss.

"What in Morgoth's name was that?" he whispered.

Gandalf's face was grave. "Things that dwell at the heart of the world, gnawing at its roots. Nameless, forgotten, yet not gone. They will not come to the surface… not until the end of days. Until then, best we leave their secrets unspoken."

He lifted his gaze to the figure before them. The Balrog.

"Ulmo's waters quenched its fire," Gandalf said grimly. "Now is our chance. We must destroy it, before its flames rekindle."

The demon turned, eyes like burning coals fixed upon them. The fear it had shown below was gone, replaced with fury. Its roar shook the stone, an echo of rage and shame.

But instead of charging, it wheeled about and fled.

"After it!" Gandalf cried, his voice cutting through the din.

In the lowest dungeons of Khazad-dûm, a vast spiral stair rose into the mountain, climbing all the way toward its highest peak. The Balrog fled upward, claws scraping stone, its molten breath echoing in the dark.

Sylas and Gandalf, borne on the basilisk Herpo, gave chase. Their brooms had long since burned away in the demon's fire, and so they pressed on with staff, sword, and wand. The endless stairs became their battlefield. Blow after blow struck in the choking dark, steel and sorcery against claw and shadow.

"Avada Kedavra!" Sylas roared, pouring all his strength into the Killing Curse. The jet of green struck true. The Balrog reeled, roaring in pain, its burning eyes dimmed, its form faltering.

Herpo lunged, coiling around the demon, his yellow eyes blazing as venomous fangs sank into the Balrog's flesh. Black fire bled where the poison struck. The monster staggered but lashed out with its claws, hurling the serpent away with a howl.

In that moment, Gandalf's white-flamed blade struck deep into its side. The light seared, and the Fire Demon bellowed in agony. Its power, already waning, ebbed further. With a shriek of fury and fear, it tore itself free and fled higher still.

Sylas and Gandalf dragged themselves onward. Their robes were torn, their skin scorched and bleeding. Every breath was ragged, heavy with smoke and pain. Sylas trembled on the edge of collapse, the Killing Curse draining him each time he spoke it, but Narya's fire still gave him enough strength to climb.

Step after step, endless as years, they ascended, until at last a cold wind struck their faces. A slanted crack of light opened before them. The stair ended at the world's crown.

They stumbled out onto the Silvertooth Peak above the Misty Mountains. A vast white wilderness stretched around them, the air sharp as knives. And there, carved in titanic stone, stood the Tower of Durin, a monument of the First Fathers.

The Balrog's body flared anew in the freezing air. Fresh flames roared from its form, and a whip of fire burst once more into its hand. Though weakened, it raged with desperate fury, its whip lashing out with heat that could melt steel.

Sylas raised his staff. "Bombarda Maxima!" His spell smashed against the fiery lash, shattering it into a storm of burning meteors that rained across the peak. Gandalf followed, summoning a surge of blinding light that hurled the demon back into the Tower of Durin. Stone cracked, walls melted, lava coursed down the ancient tower.

The basilisk struck again, hissing and coiling for the kill, when the mountain shook with a roar from below. Out of the clouds, wings spread wide, came Smaug. The dragon hurtled upward and crashed into the Balrog with a thunderous blow, his tail smashing it into Durin's Tower.

The tower could not withstand such ruin. Stones split and boulders fell in a torrent, burying the demon beneath. Its flames sputtered under the crushing weight.

"Now!" Gandalf cried.

Together, wizard, sorcerer, serpent, and dragon fell upon the Balrog in its moment of weakness.

...

On the summit of Silvertooth Peak, fire burst skyward, mingling with gleaming light as dragon cries echoed into the heavens. The violence of the clash stirred the skies themselves, clouds gathered thick and dark, and thunder rolled across the mountains.

Seeing the storm gather, Gandalf's eyes lit with fierce resolve. He lifted his staff high and shouted, his voice carrying like thunder:

"I am the messenger of wind and storm, the wielder of lightning! Flame of Udûn, here, beneath the heavens, you have no dominion!"

At his cry, the storm answered. A blinding bolt split the clouds and fell straight into his staff. Gandalf caught it, his whole form outlined in searing white fire, and with one great stroke he hurled the lightning into the Balrog.

The demon shrieked, terror flashing across its face. Flames leapt into a shield of fire, but the storm's wrath tore through it like paper. The bolt drove through its body, piercing fire and shadow alike.

For a heartbeat, time froze. The Balrog's eternal fire guttered, then went out. Its blazing form darkened, revealing a blackened, hideous husk. The mighty Flame of Udûn was suddenly frail, its inner heat dimming, its power fading into silence.

"Now, Sylas!" Gandalf cried hoarsely. "Strike its heart, finish it!"

Without hesitation, Sylas charged, clutching the divine spear Aegros. He drove it deep into the Balrog's chest, through its failing heart. The demon loosed one last, terrible scream, a sound that shook the clouds and echoed from peak to peak, filled with rage, pain, and despair.

Then it was gone. The light in its eyes flickered out. What remained was only a foul carcass of black tar and sulfur.

Sylas collapsed beside the corpse, too drained even to pull the spear free. His body was burned and battered, his magic nearly spent, every breath ragged with exhaustion. Gandalf stood opposite him, scorched and worn, his beard singed, his robes in tatters, and his staff cracked from the strain of channeling the storm.

And yet, both smiled. For the first time since entering Moria, the burden lifted.

The Balrog was slain.