The temperature in the corridor seemed to drop by several degrees.
Surrounded on all sides by members of the Order of the Phoenix and two Hogwarts teachers, Oleandra was facing some of the most formidable Witches and Wizards in all of Britain. Even Voldemort himself would have been hard-pressed to fight just three of them at once— but five? And well-trained sixth-year students besides? It was unthinkable!
And yet, Oleandra did not appear cowed in the slightest.
"Oleandra," said Remus Lupin peaceably. "I know you must have your reasons, but for Merlin's sake, please just turn yourself in until we can figure out what's going on."
"No can do, Professor," said Oleandra tersely. "I'm already running out of time."
"Enough, Lupin," Professor Snape sneered. "Miss Greengrass has made it abundantly clear on which side she stands…"
Faster than anyone could react, Professor Snape abruptly swivelled and levelled his wand at Professor McGonagall, shouting, "Stupefy!" The Stunner struck her square in the chest, and taken unawares, she crumpled into a heap, her eyes rolling back into her head.
Too focused on the immediate threat Oleandra presented, the Order of the Phoenix and the other sixth-years were a fraction of a second too slow to register Professor Snape's sudden betrayal. Unsurprisingly, Harry was the first to react— having never shared Professor Dumbledore's incomprehensible trust in the man— but unfortunately for him, Snape was one step ahead.
"You dare use my own spells against me, Potter?" Snape screamed, slicing the air with his wand and bouncing Harry's silent spell back at him. "Lazy, arrogant— just like your father! If you'd taken the lesson Miss Greengrass and I tried to teach you to heart, perhaps you'd have learned to close your mind by now!"
It was as if an invisible rope suddenly snared Harry's ankle and hoisted him into the air, leaving him dangling helplessly upside down.
"Cowards!" Harry bellowed, tears streaming up his forehead and into his hair. "Traitors! I should've known better than to trust you!"
By now, the remaining members of the Order of the Phoenix had managed to collect themselves enough to fight back. They fired a volley of Stunners at Oleandra and Snape— but Oleandra stepped in front of him, cloaking herself in Suit the Lethifold's dark form to shield herself.
"THURSAZ!" Oleandra yelled, turning to face her attackers and assuming the full stance of the thorn rune.
An invisible force tore through the corridor like an out-of-control lorry, bowling over Lupin and Tonks and hurling them into the students behind them. Neville threw himself forwards to catch them, while Ginny muttered an incantation under her breath, Conjuring a gleaming, silvery shield out of thin air that stopped Oleandra's spell dead in its tracks.
"Stupefy!" groaned Lupin as he struggled to his feet.
Oleandra drew her sword and lazily swatted away the red beam.
"Ingwaz, Elhaz, Dagaz, Gebu!" chanted Oleandra, sliding her index and middle finger along the length of her sword's blade. "Protect and Retaliate. Fragarach!"
Unfortunately, Oleandra couldn't use the Sword of the Lake against her fellow students as long as she remained enrolled at Hogwarts, but no such restrictions existed preventing her from attacking members of the Order of the Phoenix. And if the sword started floating on its own, reflecting all incoming spells… then was she really using it to purposefully hurt her fellow students?
Ginny pointed her wand at Barnabas the Barmy's tapestry, which hung opposite the entrance to the Room of Requirement. The three tutu-clad Trolls depicted within abruptly stopped dancing, sniffing the air— then stepped out of the painting one by one, hefting their roughly hewn wooden clubs.
Oleandra's eyes widened in shock as the Trolls' stench began to waft through the air. Was such a thing even possible? In any case, they certainly seemed real enough— at least to Snape. He slashed at the air with his wand, causing fabric-like rips to appear on the trolls' bodies, from which no blood emerged.
"Incendio!" shouted Oleandra.
Flames sputtered from her wand at the now mostly empty tapestry, where Barnabas sat sadly on the ground, all alone. As the edges of the work of art caught fire, the panicked image swiftly fled into the neighbouring portraits, while the three menacing Trolls were engulfed in flames from within. The textile they were made of became dotted with holes rimmed in incandescent light, which rapidly grew until nothing remained of them but cinders.
"Get out of my way, Astoria," said Oleandra quietly, as the flame-haired girl moved to block her way. "I won't ask again."
Astoria sniffled and shook her head, so Oleandra pointed her wand at her little sister. Snape and Ginny were duelling in the background, and surprisingly, the teacher seemed to be losing ground, so she had to make this quick.
"Stupefy!"
Astoria's form seemed to turn into a blur as the red beam passed through her afterimage. But as she went to knock Oleandra's wand out of her hand, the world around her seemed to spin, and suddenly, she was pinned face down against the cold stone floor.
Oleandra stepped over her body and slashed at the air, saying, "Diffindo."
The Conjured ropes binding Theo's limbs fell apart. He stood up with difficulty, rubbing his wrists.
"Come on, we'll talk later," said Oleandra, grabbing him roughly by the arm. "Professor Snape!"
"Retreat to the Room of Requirement," he grunted through gritted teeth, parrying Ginny's attacks with difficulty. "Draco left the Archway open— you'll only need to close the portal behind you. Don't worry about me. I can fly; I won't need to follow you through."
Oleandra and Theo made a break for the door, propped open with a discarded halberd. As they passed through, Oleandra gave the polearm a sharp kick, and the door slammed shut, muffling the sounds of battle outside.
The Room of Requirement was empty, save for the stone archway at the centre of the room and a few discarded articles of Dwarven weaponry and armour. There was a thin ray of light on the edge of the archway's left pillar, signifying that the magic Draco had infused it with was rapidly fading.
The door was closing, but Oleandra had no intention of going back to Nidavellir right now.
"The Time-Turner," said Oleandra, in a tone that would brook no argument, holding out her hand. "Give it to me. I know it's in your right pocket."