As Oleandra and Daphne scrambled through the door hidden behind the Fat Lady's portrait, screams of confusion erupted from both dorms. Potter and Granger's rooms had turned into whirlwinds of biting cold and miniature blizzards under the rune of snowstorms' effects. Nobody was in danger of dying unless they somehow managed to stay asleep; Oleandra had only awakened the rune to the first of its three stages.
"Spread out! They can't have got far yet!" a voice coming from the end of the hallway thundered.
It was Professor McGonagall! With all the fuss the Heir of Slytherin had caused, the number of prefects patrolling the halls at night had more than doubled, and a number of teachers had been dispatched to keep an eye on them. Daphne quietly motioned her sister to come join her in an abandoned room.
"I think I heard something," a younger voice said. "Homenum Revelio."
"In there! They're in there!"
Instantly, Daphne sprang into action, enchanting the door to make it hold fast and make it unopenable.
"Colloportus!"
"Diffindo!" cried Oleandra, using the Severing Charm to carve Elhaz, the rune of protection into the door. "This won't hold long; we need to leave immediately."
The two girls started the Tree-Portation dance, trying their best to ignore the prefects hammering on the door from the outside.
"Alohomora!" a voice chanted. "Damn it, it won't open!"
"Allow me," said McGonagall's voice. "Whoever's in there, I recommend you open this door right now, or I suggest you move out of the way!"
She waited a moment for an answer, but none came.
"Reducto," she simply said, pointing her wand at the door.
A bright jet of light surged from her wand and slammed into the door, sending splinters of wood flying everywhere, but the door stayed mostly intact.
"Eek!" cried Daphne, showered with wooden shards, interrupting her movements at a critical moment.
"Once more," said Professor McGonagall.
Oleandra's mind raced; the door wouldn't be able to take another one of those!
"DAGAZ!" she screamed, crossing her arms in front of her chest.
Daphne instantly understood what Oleandra was attempting to do as she watched the splinters of wood and clouds of sawdust reattach themselves to the door.
"I'll mirror your spell!" she cried. "DAGAZ!"
Instantly, the rate at which the door regained its integrity more than doubled. Not only that, as its time rewound, it even spat back the Reductor Curse Professor McGonagall had cast right back at her. Luckily, she managed to duck out of the way just in time before her head was turned into a fine, red mist.
"Attacking a teacher!" she screamed furiously. "Whoever you are, you're not getting out of this without an expulsion!"
She took a step back and started waving her wand, muttering an incantation under her breath. Slowly, the bricks that made up the walls of the room began to fly to her side and assemble into soldiers of stone.
At this point, Oleandra was out of ideas. They didn't have the time to start up the Tree-Portation dance again. Either she used skills that were known to be exclusive to her, indirectly giving up her identity, or she gave herself up directly.
"Kenaz, Ingwaz," she whispered, closing her eyes. "In the name of the Torch and the Divine Spark, give me the wisdom to find a way out of this situation…"
And then, the strangest solution came to her. Yes, this could work! She fished out of her pouch the slice of key lime pie she had saved for her sister.
"Sister, now is not the time for dessert," Daphne warned her.
At that moment, the wall came down, and Professor McGonagall strolled in, escorted by a dozen statues and a great number of prefects.
A bone-chilling sight appeared before her eyes; two shades stood in the middle of the room. Their appearances kept shifting, the darkness of their clothes constantly roiling, wisps of pure shadow emanating away from their ethereal bodies. Oleandra and Daphne already had Perthro drawn on themselves to conceal their identities, so they had simply altered the spell to its anti-scrying and anti-divination mode. They looked exactly like Oleandra had when she had emerged from the Archway at the Department of Mysteries!
A slew of spells flew at the shades, but they were all seemingly absorbed by the mantles of darkness.
"Revelio!" shouted Professor McGonagall, and the shades reappeared a few feet away. They had somehow dodged the Revealing Charm, which implied they didn't want their true appearance to be known!
In reality, Daphne had used Perthro's misdirection effect to make it seem like they were two feet to the left, so the prefects' spells had sailed safely past them. Safely being relative, as those spells still did a number on the wall behind them. Revelio couldn't actually miss; it just reveals hidden things around its caster. Powerful enough to break the illusion, but not enough to break the shadows concealing their appearances.
"Wunjo, Gebu, Raidhu," Oleandra chanted under her breath. "In the name of the Standard, the Gift and the Way of Transformations, turn the floor beneath me into key lime pie."
With this Galdr, Oleandra had gifted the stones directly under her the properties of a lime-flavoured custard! Raidhu helped with the transfiguration work, while Wunjo's harmonization powers spread the stones' new properties to the rest of the floor like a virus!
Custard had no load-bearing capacities whatsoever, no matter how magical it was! The ground gave way under the twins, making them fall to the floor underneath them! The spell was still working, which meant their fall was broken with even more custard. Then, they slipped through to the floor under that, and so on and so forth until they had reached the dungeons.
The twins unsteadily got up and walked back to the Slytherin common room, covered with sticky sweet and sour custard.
"Doom Desire," Oleandra told the snake guarding their common room's entrance, and they headed straight to the bathroom.
"I never want to see a slice of pie again," muttered Daphne, as she entered the shower.
As the hot water washed off the sticky residue, Oleandra thought back to her actions. Dumbledore could probably guess she was behind the prank incident from the runes she had left behind, but she supposed the old man wouldn't lift a finger until someone got seriously hurt, so they were probably safe on that front. Oleandra looked back on the spells she had used in front of McGonagall; she might have some ideas about the culprit, but no definite proof.
As she relaxed, enjoying her shower, she allowed her mind to wander. And it hit her like a ton of bricks: Tom M. Riddle, she really had known that name! He had won an award fifty years ago; the exact same year the Chamber of Secrets had been opened last time! If only she had remembered, she could have asked him if he knew anything about it! Oleandra groaned audibly. What a missed opportunity!