"Smaug, take us down!" Sylas shouted.

He and Gandalf leapt onto the dragon's back, and Smaug folded his wings, plunging into the abyss beneath Durin's Bridge.

The chasm was no dwarven carving but a natural wound in the mountain, a rift so deep that even the long-lived Khazâd had never measured its depth. Black as pitch, it seemed bottomless. The wind roared past in icy currents, cutting at their faces as they fell.

No one could say how long the descent lasted, minutes, hours, or longer. Darkness pressed in so tightly that even Sylas could barely see his own hand. Only Smaug's broad frame shielded them from the worst of the storm, giving them space to open their eyes.

Just as doubt began to gnaw at Sylas, Smaug's wings snapped open, halting their fall. The dragon's voice rumbled:

"The Balrog climbs below us."

Gandalf and Sylas peered downward. In the depths, a flicker of fire swelled into a blazing form. Against the endless black, it was unmistakable. The creature hauled itself up the sheer stone wall as easily as a spider, whip of flame lashing.

The Balrog spotted them and roared, its voice shaking the mountain. It surged upward with terrifying speed.

Sylas pulled three remaining bottles of fire-resistance potion from his cloak. One for Gandalf, one for himself, and, with some effort, he poured the last between Smaug's teeth.

The dragon shuddered as the potion coursed through him, fire in his belly snuffed out for a moment. He coughed in confusion.

"Master?"

Sylas snapped: "No flames! Don't let it slip past us. Drive it down, if it reaches water below, its strength will wane!"

A moment later, the Balrog's whip coiled around Smaug's leg. The dragon growled, but to his shock, the fire searing from the weapon no longer burned. With a vicious bite, Smaug clamped down on the flaming cord and yanked, dragging the Balrog higher before folding his wings and diving again, dragging the creature with him.

Flame and shadow writhed, engulfing them all.

The fireproof draught shielded Sylas and Gandalf from the worst of the heat, but its power would not last forever. Already, sweat stung their eyes as they plummeted with dragon and demon locked in combat.

Gandalf, bereft of his staff, drew both Glamdring and the Brsingr. With a cry, he leapt from Smaug's back, landing on the Balrog itself. He drove one blade into the creature's back, sparks flying as the steel bit against molten flesh, and slashed again with the other as they tumbled together through the void.

The roar of wind drowned all else. Sylas squinted against the gale. He gritted his teeth, raised his wand, and unleashed a spell.

"Gravitas Impello!"

A crushing weight fell upon them all. Their speed increased at once. The flames of the Balrog stretched into a long blazing tail, trailing behind them as the abyss swallowed their fall.

Sylas clung desperately to Smaug's tail to keep from being hurled away. The cold wind shrieked around them, but suddenly a damp chill rose from below.

"Master, we're close to the bottom of the abyss!" Smaug's voice rumbled back through the roaring air.

Sensing the deep waters beneath, the Balrog thrashed violently, unleashing a storm of fire that swallowed Sylas, Gandalf, and the dragon in a blazing sea. Even shielded by the fireproof draught, Sylas felt the heat scorch his lungs. Every breath was fire, his robes and satchel already crackling into ash as the contents of his enchanted bag spilled into the air, scattering like sparks into the void.

He had no time to mourn lost treasures. Gripping the divine spear Aegros, Sylas leapt straight for the Balrog's face. He plunged the weapon deep into its burning eye, pouring all his will into destruction. The spear erupted with force, tearing half of the Balrog's head apart. But its body was flame itself, its form rebuilt as swiftly as it had been broken, molten fire knitting back together in an instant.

Yet Sylas smiled grimly. That strike had staggered its mind, and in that breath of weakness they reached the abyss's end.

"Arresto Gravitas!" he cried.

In a jolt, Sylas, Gandalf, and Smaug froze a handspan above the water, their fall arrested at the last instant. Below, the Balrog crashed headlong into the black depths, the impact sending up a geyser and a shriek of steam as fire met water.

The three hovered for a heartbeat, then dropped into the freezing lake. The shock was brutal. Sylas felt as though ice had seized his veins, his heart gripped in frost. Darkness pressed in on all sides, endless and suffocating.

He conjured a globe of light, its glow piercing the waters. At once Smaug's vast outline came into view, wings thrashing to keep afloat, Gandalf still standing against the Balrog's shadowed shape.

Sylas dragged himself onto Smaug's back, shivering but safe from the cold's deadly grip. Gandalf's voice rolled like thunder through the waters:

"Foul spirit, this is the domain of Ulmo, Lord of Waters! You hold no dominion here!"

The words rang true. The Balrog's fires sputtered and died in the abyss, leaving only a sludgy darkness where its form had once blazed. Though it still loomed vast and menacing, its might was halved, no greater now than Gandalf himself.

"Master! Down here!"

The hiss came suddenly from the depths. A great serpentine form glided from the shadows: Herpo. His golden eyes were shut tight, but his voice carried clear in Parseltongue.

Sylas blinked, stunned, then laughed in sudden relief. When the Balrog had dragged both Herpo and the Watcher into the chasm, he had feared the basilisk lost. Yet here he was, very much alive.

"Herpo, aid Gandalf! Use your fangs, your venom, whatever you can, strike the Balrog!"

The basilisk needed no second bidding. Herpo surged through the water, vengeance burning within him. He remembered well how the Balrog had hurled him into the abyss. Now he struck back. Diving beneath the demon, he lashed upward, sinking his fangs deep into the Balrog's leg and pumping venom into its form.

The Balrog bellowed in rage. Its fire-born body could not be slain by poison, yet the venom seared its spirit, slowing its movements.

Meanwhile, Sylas worked furiously, summoning back the scattered relics from his ruined satchel with Summoning Charms. One wand-flick drew Gandalf's staff back into his grasp.

"Your staff!" Sylas shouted, hurling it to him.

Gandalf caught it as if it were his very breath. Staff in hand, he unleashed a surge of white light that hurled the Balrog back. Sylas's own voice followed, harsh with power:

"Avada Kedavra!"

The killing curse struck the weakened form, wringing another shriek from the demon as its shape guttered. It reeled, faltered, and fled, retreating into a tunnel carved deep within the mountain.

"After it!" Gandalf barked. "Do not let it recover!"

But the tunnel was too narrow for Smaug's wings. Reluctantly, Sylas dismissed the dragon, sending him to rejoin the watcher above. He mounted Herpo instead, pulling Gandalf with him onto the serpent's broad back. Herpo's senses were keen; he slithered through the labyrinth with unerring instinct, following the stench of fire and brimstone.

As they raced onward, Sylas noticed Gandalf's face pale in the gloom. The wizard's voice was low, almost reverent with dread.

"May the Valar guard us… these tunnels were not made by dwarves. Nor orcs. Other things dwell here, creatures nameless and forgotten. Things even Sauron never mastered."

Sylas frowned, uneasy. "What things?"

"I cannot tell you," Gandalf murmured, "and you would not wish to know. I only pray we do not wake them."

Yet his words proved ill-omened.

Ahead, they caught the Balrog's trail, only to see the great demon itself recoil. For the first time it gave voice not to rage, but to fear: a short, sharp whimper, filled with raw panic. It turned and fled for higher ground, abandoning all thought of battle.

"Quickly!" Gandalf urged. "Do not linger!"

Even the basilisk, proud and deadly, seemed desperate to escape what stirred in the dark behind them. Sylas clung to the serpent's ridged spine, knuckles white.

The mountain shook as if the world itself trembled. Pebbles and dust rained from the vaulted stone above.

And then, silence. Not true silence, but an awful stillness, as though every sound had been swallowed. The echoes of pursuit, the rush of breath, the beating of hearts, gone. A darkness deeper than shadow pooled in the tunnel, an absence of being itself.

Whispers rose, not to his ears but to Sylas's very soul. Ancient, hungry, incomprehensible. Malice without shape, hunger without end. Fear, pure and primal, gripped him, coiling around his heart.