Fawkes burst from Dumbledore's pocket, spreading his golden-red wings.
With a clear, ringing cry, the phoenix soared upward, circling beneath the cavern's high dome. Its voice echoed through the cold stone, driving back the oppressive darkness for a fleeting moment.
"Master!" rasped a voice, shattering that brief silence.
Sean Rivera stumbled out from the shadows, his gaunt face contorted in a look of desperate joy.
"Dumbledore followed the Muggles here!" he cried, running toward Voldemort. His tattered robes trailed through the damp floor, leaving a dark streak. "I didn't say anything... I didn't tell-"
Voldemort's red eyes narrowed dangerously. Without hesitation, he dropped the still-twitching wizard in his grasp and slashed his wand downward.
"Avada Kedavra!"
A flash of green light. Sean's words froze on his tongue. His body went rigid, the light in his eyes extinguished in an instant.
He collapsed like a puppet with cut strings, falling between Dumbledore and Voldemort. Dust rose from the impact and drifted lazily in the dim light reflected off the lake. His hollow eyes stared blankly upward, his lips twisted in one last grotesque smile.
"How touching, this little reunion, my dear teacher," Voldemort whispered, running pale fingers along his yew wand. His thin lips curved into a cruel smile. "Especially in the place where you're going to die."
"For a man of sound mind, Tom," Dumbledore said quietly, looking at the face before him, so twisted it could barely be called human, "death is but another great adventure. But I'm afraid today will not be the beginning of mine."
Voldemort's snake-like nostrils flared. His expression contorted.
"Familiar rhetoric," he hissed. "Did you follow these filthy Muggles all the way here, Dumbledore? It seems the Lestranges failed to heed my orders."
"I believe so," Dumbledore replied, moving with slow precision, never taking his eyes off Voldemort. "Tell me, Tom, why do you need so many Inferi? Murder is the darkest of acts."
"You're still as sanctimonious as ever," Voldemort said softly. His red slit pupils gleamed coldly in the dark. His wand twitched, barely visible.
At the same instant, Dumbledore flicked the Elder Wand. A gray wall of dust surged up between them, absorbing the silent curse.
"I must say, your mischief grows uglier with age, Tom."
"Ugly?" Voldemort barked out a laugh so sharp it shattered the stillness. The ripples stirred the lake, and several pale hands broke the surface before sinking again. "You have no idea what greatness I am achieving!"
He slashed his wand, and shards of rock on the ground morphed into dozens of serpents, tongues flicking as they lunged for Dumbledore.
Dumbledore rotated his wrist lightly. The stone snakes unraveled mid-air into ribbons, drifting harmlessly to the floor.
"Transfiguration, you taught me that, Professor," Voldemort sneered, directing his wand toward the lake. The water began to boil, rising into sharp jets that shot toward Dumbledore.
Dumbledore's robes flared as he conjured a whirling shield of fire. Each jet of water turned to steam on contact.
"I see you paid attention in class, Tom," Dumbledore remarked calmly, as though discussing the weather. "But your technique remains too showy. I told you once, true transfiguration should leave no trace."
He waved his wand, sending a beam of white light hurtling at Voldemort. The Dark Lord conjured a gleaming silver shield to block it.
Whatever spell Dumbledore had used didn't seem to damage the shield, but it made the metal hum with a deep, gong-like resonance. Voldemort flung it away immediately.
Their wands traced intricate patterns in the air, bolts of light weaving and colliding across the cavern.
Dust filled the air. In the corner, the bound Muggles began to stir. A middle-aged woman awoke first and whimpered in terror.
Voldemort's red eyes snapped toward the sound. A cruel smile crept over his mouth.
"Ah, our audience is awake." He turned his wand toward them. "Let's give them a better show. Avada Kedavra!"
The blinding green light streaked toward a young Muggle boy who had just managed to sit up.
Dumbledore stepped forward instantly. With a flick of the Elder Wand, a rock sprang to life and leapt into the spell's path. The Killing Curse struck it, exploding in a shower of sparks that shook the cavern.
Seizing the moment, Dumbledore waved his wand and the ropes binding the Muggles fell away.
"Hide behind the rocks!" he ordered quietly, his voice carrying irresistible authority.
The terrified Muggles scattered, some stumbling for cover, others frozen in shock at the spectacle before them.
"How noble, Dumbledore," Voldemort taunted. "Wasting your strength on insects?" He cast several more Killing Curses, which Dumbledore dodged or deflected with expert precision. "Do you think you can save them all?"
One Muggle man failed to move fast enough. The green light struck him, and he collapsed soundlessly.
Pain flickered across Dumbledore's eyes, but he did not falter.
"They are not insects, Tom," he said. "Every life is worth saving. That is something you will never understand."
"Then die with them!" Voldemort snarled, his face twisted in rage.
He unleashed a torrent of spells like a storm of death. Dumbledore moved with astonishing grace, countering with defensive charms and transfigurations. Pools of water became transparent shields; stalactites turned into whirling blades; moss along the walls grew into strong vines that lashed toward Voldemort's legs.
Beams of colored light ricocheted through the cave, each impact shaking the stone and sending pebbles raining down.
In the chaos, a sudden Killing Curse shot from Voldemort's wand at an impossible angle. Dumbledore had just blocked another spell, he could not evade in time.
At that instant, a golden-red flash streaked downward.
Fawkes dove, opening his beak wide and swallowing the green light whole.
Flames engulfed the phoenix. In seconds, the blaze shrank until only a tiny, featherless chick lay trembling on the ground, unable to fly.
"Fawkes!" Dumbledore called.
The newborn phoenix chirped weakly. Between spells, Dumbledore scooped it up and tucked it safely into his robe.
"You've wasted your last chance at salvation, Dumbledore," Voldemort said, eyes gleaming with triumph. "Now who will save you, old man?"
He aimed his wand at the black lake.
The surface boiled violently. From its depths rose dozens, hundreds, of pale Inferi.
Their swollen hands clawed at the rocks, dragging themselves ashore. Hollow eyes stared in unison at Dumbledore. The stench of decay filled the cave.
Dumbledore drew a deep breath and traced a complex rune in the air.
Flames erupted from the darkness, expanding outward. A blazing golden-red ring of fire encircled the lake's edge.
The Inferi staggered, unsteady, as if dazed by the heat. Then the ring twisted, transforming into a massive fire-beast that roared and hurled itself upon them. Wherever it passed, corpses crumbled to ash.
Voldemort's expression darkened. He summoned more Inferi while hurling curses toward Dumbledore.
Fire and shadow clashed. Heat waves shimmered in the air.
Sweat beaded on Dumbledore's forehead. Controlling the fire required immense focus, and he had to protect the remaining Muggles at the same time.
Then Voldemort's lips curled in a triumphant sneer.
The ashes of the destroyed Inferi did not vanish. Instead, they thickened into black mist that enveloped Dumbledore. Faces twisted in silent agony swirled within it.
Dumbledore gasped, the mist was alive, clinging to him, burning against the light of his fire.
"Soul Corrosion..." he realized too late. Cold pierced his body, as if countless hands were tearing at him from within.
"Perhaps it's time to say goodbye," Voldemort's voice echoed from beyond the fog, filled with delight.
Dumbledore, straining, directed the phoenix-fire toward the Dark Lord. As it passed through the black mist, the flames turned pitch-black, merging with it, but their power did not wane.
Voldemort hadn't expected that. With a startled cry, he leapt aside. Most of the fire missed him, but a few tendrils struck his left arm.
A hideous scream tore from his throat. His sleeve burned to ash, revealing charred flesh beneath.
"You... will pay for this!" he gasped, eyes bloodshot with fury. He pointed his wand at a Muggle hiding behind a rock.
The unfortunate man was yanked forward by invisible force and slammed into the cavern wall. There was a sickening crack. Blood streamed down his face as his body slid lifelessly to the floor.
"No!" Dumbledore shouted, but exhaustion slowed him, he was too late.
The man's blood pooled, seeping into the stone.
The archway flared open again, responding to the sacrifice.
Voldemort, trembling, dragged himself toward it. Each step was labored, every breath a rasp.
He braced a hand against the rocks, then turned back to look at Dumbledore one last time.
"We shall meet again," he hissed, and vanished through the gate.
Dumbledore tried to follow, but the mist's corruption and his drained magic overwhelmed him. His vision blurred. Knees buckling, he dismissed the fire-beast before collapsing onto the cold stone.
His last awareness was of the muffled sobbing of the surviving Muggles.
...
No one knew how much time passed before five Muggles finally crept out from hiding, trembling.
They stared in horror at the devastation around them, ashes, scorch marks, and the bodies of their dead companions.
"Oh God... what is this place..." a middle-aged woman whispered, hugging herself and weeping.
"We have to get out!" said a young man with cracked glasses, his voice shaking. "Before that... that monster comes back!"
"How?" a gray-haired man holding his son pointed to the sealed archway. "The door's closed!"
Then, a silent red-skinned man approached the corpse near the wall. Kneeling, he pressed his bleeding hand to the stone.
The rock shimmered faintly, the archway reappeared.
"I knew it," he rasped. "That monster used blood to open it! Quick, let's go!"
The others gasped with mingled terror and hope, rushing toward the gate. But one of them stopped, pointing at Dumbledore's unconscious form.
"What about him? We can't just leave him."
"He's one of them!" the bespectacled man snapped. "What if he's with the monster?"
"But he saved us," the gray-haired man said, clutching his son tighter. "We can't just abandon him..."
The others hesitated, but fear won out. One by one, they fled through the archway without looking back.
The gray-haired man drew a shaky breath, went to Dumbledore, and slung the unconscious wizard's arm over his shoulder.
But just then, a scream pierced the air from beyond the gate.
"No-!"
The sound was so horrifying that both survivors froze where they stood.
Moments later, silence.
The man turned, trembling. The archway's light had vanished. The cave fell silent and dark once more, save for the faint green glow from the lake's heart, and their ragged breathing.
...
Hogwarts. Black clouds roiled outside the windows.
McGonagall stood in the Headmaster's office, clutching a note left by Dumbledore.
"What are you doing, Albus?" she murmured, reading the familiar slanted handwriting.
"Minerva, take out the boat. Repair and prepare it for immediate use. If I do not return in time, gather all Muggle-born students and leave Hogwarts. Take whatever you can. Severus Snape will assist you..."
She lifted her eyes to the darkening sky beyond the window. For the first time, the ancient walls of Hogwarts no longer seemed unbreakable.