Fawkes darted from Dumbledore's pocket, spreading his crimson and gold wings. With a clear, ringing cry, the phoenix soared upwards, circling the dark cavern ceiling. The sound echoed amongst the cold stone walls, momentarily dispelling the surrounding gloom.
"Master!" A hoarse voice suddenly shattered the brief stillness. Sean Rivera stumbled out of the shadows, a look of wild ecstasy on his gaunt, sunken face. "Dumbledore tracked those Muggles here!" He rushed towards Voldemort, his ragged robes trailing a wet mark on the ground. "I didn't say anything—I didn't tell him a thing—"
Voldemort's red eyes narrowed dangerously. He flung the twitching wizard he held, and without a moment's hesitation, swept his wand downwards in a sharp, slicing motion: "Avada Kedavra!" A flash of green light, and Sean's words abruptly ceased. His body stiffened for a second, the light in his eyes abruptly extinguished. He toppled like a puppet onto the rocky floor between Dumbledore and Voldemort, the stirred dust slowly settling in the faint lake-light. His hollow eyes were still wide open, a strange, last smile fixed on his lips.
"What a touching reunion, my dear teacher," Voldemort's pale fingers stroked his yew wand, a cruel smile gracing his thin lips. "Here, in the place where you are about to die."
"To the well-organised mind, Tom, death is but the next great adventure," Dumbledore watched Voldemort's face, now almost devoid of human features, a wave of sorrow washing over him. "But I fear today is not yet my new beginning."
Voldemort's face twisted for a moment, his snake-like nostrils flaring slightly. "Familiar rhetoric," he hissed. "Did you follow these filthy Muggles to this beautiful vista, Dumbledore? It seems the Lestranges have not adequately heeded my instructions."
"I believe so," Dumbledore moved slowly, his eyes never leaving Voldemort. "What do you need so many Inferi for? Murder is the vilest of acts."
"Still so self-righteous," Voldemort whispered. His crimson vertical pupils gleamed coldly in the darkness, and his wand gave an almost imperceptible flick. Dumbledore almost simultaneously swung the Elder Wand, and a grey shield of dust instantly appeared between him and Voldemort, blocking an unspoken Cruciatus Curse: "I must say, your pranks are growing increasingly unpleasant, Tom."
"Unpleasant?" Voldemort let out a grating laugh that disturbed the Inferi beneath the lake's surface; several pale hands emerged from the water only to sink back, dimly visible in the ripples. "You simply don't comprehend the magnificent work I am undertaking!"
As his words faded, Voldemort's wand snapped upwards, and the scattered stones on the ground suddenly transformed into dozens of venomous snakes, hissing and darting towards Dumbledore. Dumbledore's wrist flicked lightly, and the stone snakes instantly turned into ribbons, fluttering in the air before falling to the ground.
"You taught me Transfiguration, teacher," Voldemort sneered, pointing his wand at the lake. The water boiled, forming dozens of water arrows that shot towards Dumbledore. Dumbledore's robes flapped in the sudden current of air, as he conjured a spinning shield of fire; the water arrows turned to steam upon contact.
"I see you paid attention in class, Tom," Dumbledore commented, his voice as calm as if discussing the weather. "But your technique is still too obvious; remember what I told you, elegant Transfiguration should leave no trace."
Dumbledore waved his wand lightly, and a white light sped towards Voldemort. Voldemort conjured a shimmering silver shield out of thin air to block it. What spell this was, it seemed to cause no visible damage to the silver shield, but the shield emitted a low, gong-like vibrato. Voldemort hastily threw the silver shield aside.
Both their wands traced intricate paths in the air, the light of their spells weaving and criss-crossing in the darkness. Amidst the swirling dust, the bound Muggles in the corner slowly began to awaken. A middle-aged woman was the first to open her eyes, letting out a frightened whimper.
Voldemort's crimson eyes immediately turned towards the sound, a cruel smile curving his lips. "Ah, our audience awakens," he redirected his wand. "Allow me to give them a more spectacular performance. Avada Kedavra!" A blinding flash of green light streaked directly towards a Muggle boy who had just struggled to his feet.
Dumbledore immediately stepped forward, swinging the Elder Wand; a rock instantly came alive, leaping from the ground into the path of the Killing Curse. The green light collided with the stone shield, erupting in a blinding shower of sparks that shook the entire cavern. Seizing this brief interlude, Dumbledore swiftly untied the Muggles' ropes.
"Quickly, hide behind the rocks!" he commanded the terrified group in a low voice, a tone of unmistakable authority. The Muggles scattered in panic, some stumbling behind rocks, others frozen in place, utterly bewildered by the magical duel unfolding before them.
"What noble mercy, Dumbledore!" Voldemort laughed. "Wasting your magic for these ants?" He shot several more Killing Curses, all deftly dodged or blocked by Dumbledore. "Do you think you can save everyone?"
A Muggle man, unable to dodge in time, was struck by a curse and fell silently. A flicker of pain crossed Dumbledore's eyes, but he did not falter, continuing his duel with Voldemort.
"They are not ants, Tom," he said. "Every life is worth saving—a truth you will never comprehend."
"Then die with them!" Voldemort's face contorted with fury. He wildly brandished his wand, a barrage of deadly curses raining down on Dumbledore. Dumbledore dodged with astonishing agility, simultaneously retaliating with various intricate defensive and Transfiguration spells. He transformed puddles on the ground into transparent shields, stalactites into flying daggers, and even caused moss on the rock walls to grow into tough vines, attempting to ensnare Voldemort's feet.
Lights of every colour sprayed across the cavern, each collision shaking the rock walls and sending fragments tumbling. Amidst this fierce exchange, a swift Killing Curse suddenly shot from Voldemort's wand tip, at such an angle it was almost impossible to evade. Dumbledore had just parried another spell, and was about to be struck by the green light.
In a flash, a golden-red figure swooped down. Fawkes opened his beak wide, swallowing the green light whole. The phoenix erupted in a dazzling blaze. It rapidly shrank within the fire, finally landing on the ground, transformed into a crumpled, featherless chick, unable to fly.
"Fawkes!" Dumbledore cried. The young Fawkes weakly chirped on the ground, and Dumbledore, in a lull between spells, swiftly scooped him into his robes pocket.
"You've just wasted a precious chance to save yourself, Dumbledore," Voldemort's eyes gleamed with triumph. "Now, who will save you, old man?" He aimed his wand at the black lake water.
The calm surface of the lake began to boil, churning violently. Dozens, hundreds, of pale Inferi floated up from the bottom. Their skeletal heads and hands emerged from the murky water, their pale, bloated hands clutching the rocks at the shore, beginning to crawl onto land, their hollow eyes all fixed on Dumbledore. The stench of decay instantly filled the entire cavern.
Dumbledore took a deep breath, his wand tracing a complex rune in the air. Roaring flames appeared in the darkness, rapidly expanding in the air. A bright, golden-red ring of fire encircled the lake's edge. The Inferi, one by one, staggered, their bodies swaying. Then, the ring of fire transformed into a colossal beast; it roared and charged into the horde of Inferi, turning them to ash wherever it went.
Voldemort's face darkened, as he continuously summoned more Inferi, simultaneously searching for an opportunity to attack Dumbledore himself. Fire and shadow intertwined in the cavern, the heat making the air ripple. Sweat beaded on Dumbledore's forehead. He had to concentrate to control the fiery creature, while also protecting the innocent Muggles.
Suddenly, Voldemort's face twisted into a malevolent, triumphant sneer. The ashes left by the burned Inferi did not vanish, but instead transformed into a thick black mist, rapidly enveloping Dumbledore. The mist seemed to contain countless screaming, voiceless, tormented faces. Dumbledore felt a suffocating sensation; the mist, as if alive, coiled around him, hissing under the illumination of the fire.
"Soul corruption," he realised he had fallen into a trap. A bone-chilling cold swept over him, as if countless icy hands were tearing at his body.
"Perhaps it's time to say goodbye," Voldemort's voice came from outside the black mist, laced with triumphant glee.
Dumbledore, clinging to consciousness, forced the magical fire to turn towards Voldemort. As the golden-red flames passed through the black mist, they strangely merged with it, turning a sinister black, yet losing none of their power. Voldemort evidently hadn't anticipated this change. He let out a startled cry, hastily dodging, barely avoiding most of the flames, but a few tendrils of black fire grazed his left arm. He shrieked, a sound not quite human, as his robe sleeve instantly turned to ash, revealing a charred arm beneath.
"You—you will pay for this!" Voldemort gasped, pointing his wand at his injured arm, his eyes even redder from being bloodshot. He suddenly aimed his wand at a Muggle hiding behind a rock. The poor person screamed as they were yanked out by an unseen force, then violently flung against the rock wall with a sickening thud. His body slumped against the stone, blood pooling from his head, utterly still.
"No!" Dumbledore wanted to stop it, but at that moment, his movements were too sluggish, and he failed. The Muggle's body left a long streak of blood as it slowly slid down the stone wall to the ground. The blood, as if drawn, flowed into the depths of the rock.
Receiving this offering of blood, the archway immediately reopened, revealing the blurred scene outside. Voldemort struggled to crawl towards the archway, each movement accompanied by painful gasps. He propped himself up with his right hand on a rock, and before disappearing, he cast one last look at Dumbledore.
"We will meet again," he said, using his last ounce of strength to lunge through.
Dumbledore tried to pursue, but the erosion of the mist and the excessive drain on his magic finally made him unable to stand. His vision began to blur, his knees buckled, and he barely managed to dispel the fiery beast before collapsing onto the cold ground. In his fading consciousness, he heard the muffled weeping of the Muggles.
---
Who knows how much time passed, but the five surviving Muggles finally timidly peeked out from their hiding places, their faces etched with fear and confusion. They stared in horror at everything before them: piles of ash, charred marks, and the bodies of their unfortunate companions.
"Oh, God, what is this place?" a middle-aged woman sobbed, clutching her arms tightly.
"We have to get out of here!" a young man with a cracked spectacle lens said, his voice trembling. "Before that—that monster comes back!"
"How do we leave? The door's closed!" another grey-haired man, embracing his son, despairingly pointed at the re-sealed archway.
Just then, a red-skinned man who had been silent all this time suddenly walked towards the body. He knelt down, trembling, and pressed his injured hand against the stone wall in front of him. The stone glowed again, and the archway appeared.
"I knew it!" he rasped. "That monster did it that way! Quick, let's get out of here!"
The other Muggles, caught between shock and relief, scrambled towards the archway. But one of them suddenly stopped, pointing at the unconscious Dumbledore and asking, "What about him? We can't leave him."
"He's a monster too!" the spectacled young man snapped. "Who knows if he's with that one who left!"
"But he saved us!" the grey-haired man said hesitantly, holding his boy. "We can't just leave him here..." The other three hesitated for a moment, but ultimately, fear overcame their conscience, and they bolted through the archway without looking back.
The man took a deep breath and slowly walked towards Dumbledore, placing the old wizard's arm over his shoulder, laboriously trying to help him to his feet. However, almost instantly, heart-wrenching screams came from outside the door.
"No—!"
The sound was so dreadful it made the two remaining in the cavern tremble. The screams quickly ceased, leaving only a bone-chilling silence. The man looked in horror towards the source of the sound. The archway's light vanished again, and the cavern plunged back into silence and darkness, leaving only his trembling breaths and that eerie green light in the middle of the lake.
---
Hogwarts. Outside the window, dark clouds churned. Professor McGonagall stood by the Headmaster's office window, her fingers tightly clutching the note Dumbledore had left.
"What on earth is Albus going to do?" she murmured to herself, her gaze sweeping over the familiar, slightly slanted handwriting on the note.
"Minerva,
Please immediately retrieve the boat, prepare it after maintenance, and be ready to depart at all times.
If I do not return in time, please gather all Muggle-born students, leave Hogwarts, and take everything you can. Severus Snape will be able to help you."
She looked up at the increasingly dark sky outside the window, feeling for the first time that Hogwarts' walls no longer seemed so impenetrable.