The first thing Oleandra saw upon opening her eyes was a void of pitch-black nothingness. Despite her Mystic Sight, she could not even see her own hand, even if she waved it two inches from her face. Merlin had assured her she'd be home by the time she opened her eyes again, so… where on Earth was she now!?
She pricked up her ears, feeling blindly in front of herself in hopes of running into something, anything. The muffled sounds of screaming and shouting drifted in the distance, reminding her of Merlin's warning that things might be slightly hectic upon her return.
But if she had indeed returned exactly to the spot she had left, she was in Hogwarts Castle— but who would dare invade this sanctum while Dumbledore still lived?
"Come on, hurry up, they're coming from upstairs! Luna's still trapped up there!" Ron's voice rang out from behind Oleandra. The voice was accompanied by a stampede of footsteps. "Bloody hell, is that Peruvian Instant Darkness Powder? What were Fred and George thinking, selling that stuff to Malfoy!?"
"Where are you going?" Astoria's distinct voice cut through the hubbub. "That's the wrong way!"
"Have you seen Tracey!?" came Daphne's urgent voice.
Oleandra was about to call out to her sisters, when the rune of distress suddenly began ringing loudly within her inner world.
'Naudhiz!'
Without hesitation, she threw herself to the floor, just as a bolt of green energy streaked over her head. In response, a storm of red beams burst forth from the opposite side, briefly illuminating the darkness as they flew over her head.
Hearing footsteps rapidly approaching, Oleandra rolled to her left until she hit a solid wall. Gripping the Sword of the Lake's pommel in her right hand, she scrambled upright and broke into a crouched run, her left hand skimming the wall to guide her steps.
"I 'ear summun comin'!" a gruff voice rang out.
"Hold your position, you filthy half-pints!" roared another. "It'll be your heads if any of the teachers break through!"
Oleandra's pace accelerated into a sprint. If a Killing Curse hit one of her sisters, she would never forgive herself.
"ELHAAAZ!" she roared, extending her index, middle and ring fingers as she ran.
What awaited Oleandra as she burst through the foggy, rolling darkness surprised her just as much as her sudden appearance surprised her enemies. Evidently, they had not been expecting a tall, wild-looking girl in tight, form‑fitting snakeskin robes leaping at them with a medieval sword in hand… but neither had she been expecting to see a blonde, middle-aged Wizard in dark robes directing a platoon of Nidavellir Dwarfs in full plate armour!
Oleandra took the surprise in stride, soaring above the Dwarfs' pikes, halberds, and tower shields before alighting on one's head. Before he could react, she lightly sprang into the air once again and hurled herself at the Wizard behind them— a Death Eater if ever she had seen one.
"Thursaz!" Oleandra shouted, curling her index and thumb and extending the rest of her fingers.
The unfortunate Death Eater could only gape at her in shock as what felt like a small lorry slammed into him, flinging him into the stone wall behind. Eyes rolling, he slid to the floor and did not get up again.
"Don't you recognise star magic!?" a Dwarf clad in golden armour roared. "Kneel, you fools! You dare stand in the presence of an Aesir goddess?"
The entire platoon prostrated themselves, but Oleandra had already vanished up the stairs. Having been hurled into the past not too far from where Professor Slughorn's office was located, she knew that the next floor up would be the seventh— the Room of Requirement's floor!
"More of them!" Oleandra groaned, watching as wave after wave of Dwarfs marched out through the Room of Requirement's entrance. "What in Merlin's briefs has Malfoy done now?"
…
Realising that, by sneaking the Dusk Elf into the castle on that fateful night, he had made himself an accessory to Oleandra's murder— or at the very least, to her permanent disappearance—Draco had fled in a panic to the seventh floor. There, he summoned the Archway hidden in the Room of Requirement and escaped to the City of Gateways in Nidavellir, knowing full well that Dumbledore could never follow him there— or at least, not without carving the twenty-four star runes into his very soul.
True to its name, the City of Gateways was home to eight great stone archways— gateways to the other realms under Asgard's dominion. Long ago, the Aesir had conquered the Dwarfs' realm and assembled all their planet's Nine Realms Archways in one place, purely for the sake of their own convenience.
Draco had passed through each of the Archways, save for those leading to Svartalfheim, Vanaheim, and Asgard, which were barred to him. Claiming his runic magic as proof of godhood, he had raised an army of Nidavellir Dwarfs, and for months they had explored the worlds beyond the Archways. At last, he discovered the Alfheim–Midgard portal— his way back to Earth, and a means of smuggling Death Eaters into Hogwarts.
…
"MALFOOOY!" Oleandra bellowed, attracting the attention of every single soul in the corridor. "You left the bloody door open again, you blithering idiot!"
With a single word, the azure grimoire speckled with golden stars leapt from her hip and hovered before her, its pages fluttering open to the place she'd marked with a ribbon. Oleandra slammed her palm down on the intricate runes inscribed on the pages, taking flight as green and light-blue bolts of magic started flying in her direction.
"Ægishjálmur ahead, Ægishjálmur behind, Ægishjálmur in my left hand, Ægishjálmur in my right hand, Ægishjálmur above, Ægishjálmur below— PROTECT!"
This time, the Dwarven Army reacted with open hostility to Oleandra's magic, which appeared behind her as a fiery tapestry of the same intricate Lokk repeated six times in flaming lines like a honeycomb.
"The Rune of the Serpent!" one cried in horror. "The evil dragon Fáfnir!?"
"We're doomed! The Spawn of Níðhǫggr has come!"
But most of the Dwarfs were made of sterner stuff.
"Stand your ground, worms!" their commander clad in gold roared, banging his pike against his tower shield. "Defend the gods!"
How many times had the Dwarfs of Nidavellir repelled that colossal Lindworm, when it came to snatch up their sheep, their Frost and Fire Giant slaves— and sometimes, they themselves? Fáfnir had once been their greatest smith, but in the end, he became their greatest sinner, turning himself into a mindless monstrosity in a vain attempt to wield the Aesir's magic against them.
Oleandra naturally vividly remembered the gigantic Lindworm Dragon that had almost snapped her up in Ginny's flying yellow car in her third year at Hogwarts…