"Duck, Mai!" Oleandra yelped, drawing her wand. "Arresto Momentum!"
The first of the golden grilles continued its course, embedding itself deeply in the doorframe mere inches from Oleandra's nose, but the other froze in midair. Bellatrix instantly slid beneath it and promptly leapt back to her feet and continued her mad dash, but unfortunately for some of her Death Eater companions, not all were as quick to react when the grille came to an abrupt halt.
As they ran out of the lift after Bellatrix, Thorfinn, Goyle, and a few others struck their heads against the metal grille suspended in midair with a series of resounding gongs, and they toppled over backwards, their feet flying into the air.
"Expulso!" Bellatrix screeched.
Mai swung her wand arm in a wide arc behind her as she ran to the door.
"Protego!" she cried.
A translucent, silvery dome appeared behind her, shimmering and shaking as a terrifyingly loud explosion detonated point-blank across its surface in a flash of blinding blue light. Almost immediately, the magical shield shattered, letting the light spill through the fissures.
"Elhaz!" Oleandra shouted.
She assumed the stance of the Cygnus constellation and threw herself in front of Mai as she ran through the doorway, taking the brunt of the explosion with Suit the Lethifold's help. The shockwaves hit her like a lorry, and she went crashing through the coffee table between the sofas and into the Department Head's desk at the opposite end of the room.
Dazed, Oleandra rolled onto her stomach, trying to push herself to her feet…
"Hogwarts!" Mai called, her voice accompanied by the whoosh of flames. "Up we go!"
Oleandra felt a lurch as someone tugged her up by the arm, and before she knew it, she was falling headlong into the emerald flames of the fireplace. The world was spinning dizzyingly around her, the flames roaring in her ears… and before she knew it, she was stumbling out of a different fireplace, and she fell to her knees.
"Mai!" Oleandra gasped, scrambling to face the fireplace.
The flames roared as they turned emerald green, and Oleandra fumbled at her robes for her wand, pointing it at the fireplace in case Mai was not the one to come through, and she waited for a few excruciating seconds… but in the end, the flames returned to their normal colours, and the fire died down without anyone having come through.
Oleandra's hands shook slightly.
"Reducto," she said.
A jet of blue light flew from her wand and vaporised the fireplace. If Mai had not come through in the last few seconds, then she would not be coming at all. Better to destroy the fireplace so that nobody could come after her…
"Miss Greengrass."
Oleandra limped over to the Headmaster's desk and lowered herself into the empty chair. She looked up at Dumbledore's portrait hanging above her head, and he peered down at her over his half-moon glasses with his piercing blue eyes.
"Professor Dumbledore," Oleandra said with difficulty.
From Oleandra's perspective, she could see the long line of people walking up to the castle from Hogsmeade through the window past Dumbledore's portrait. Every so often, Wizards and Witches would Apparate at the castle grounds' gates, and they would help usher in the refugees, most of whom were having trouble walking towards the castle due to the powerful Muggle-Repelling Charm that had been placed over the grounds.
"It seems the point of no return has at last arrived," the old man in the portrait said softly. "I had hoped Hogwarts would not turn into a battleground… but it seems it was inevitable that all would end where it began."
Oleandra remained silent.
"Professor Lockhart has told me everything," Professor Dumbledore went on. "To think you would decipher the secrets of my old diary… no, I suppose I should have expected as much. I am deeply thankful that you have not abandoned Harry."
His gaze fell on the golden cup hanging at her waist.
"With the destruction of Hufflepuff's cup, all nonliving Horcruxes will have been accounted for," Professor Dumbledore said. "Now only Miss Ginevra Weasley, Miss Daphne Greengrass, and Lord Voldemort remain… along with two others."
"Two others?" Oleandra asked hoarsely. "How do you mean?"
The diary which had possessed Ginny.
The ring.
The locket.
The diadem.
The cup.
The fragment that had been transferred from Nagini to Daphne.
Lord Voldemort himself.
According to Harry, Voldemort had split his soul six times, for a total of seven pieces.
"It was indeed Tom's design to create six Horcruxes, for seven is one of the most powerful and stable magic numbers," Professor Dumbledore said impassively. "However, he did not account for the fact that as he continued to haphazardly mutilate his soul, it would become weaker. Brittle, even."
Oleandra said nothing.
"Fifteen years ago, Lord Voldemort went to Godric's Hollow to murder baby Harry, the first of the two children who had been prophesied to become his ultimate enemy," Professor Dumbledore explained. "With the express intention of making him his sixth and final Horcrux… and though he failed in one of his aims, he did accidentally succeed in the other… so wounded was his soul that, when his curse rebounded, it split again… and, finding itself unhoused, the fragment of soul entered the closest container it could find…"
"Harry," Oleandra whispered. "Then, for Voldemort to finally defeated, Harry has to… die?"
Professor Dumbledore nodded gravely.
"Harry told me that, on the night Lord Voldemort first returned, at the conclusion of the Triwizard Tournament, he used the Killing Curse upon you," he continued. "Through some miracle I cannot even begin to fathom, you survived… making you the second person, after Harry, to withstand a direct hit from a full-powered Killing Curse."
Oleandra smiled wryly. "I sacrificed myself to save myself," she said simply.
"Indeed," Professor Dumbledore said, nodding. "But the outcome was the same: you survived, and a sliver of Lord Voldemort's soul came to attach itself to your own."
Oleandra felt as though her blood had turned to ice in her veins.