Daphne's eyes narrowed dangerously.
"Sister," she said softly. "Need I remind you of our… unique situation? This is hardly the time to be playing hero with the Gryffindors."
Hermione's eyes widened in understanding. She was a smart Witch; she immediately made the connection between Daphne's words and the fact that Astoria had spent her summer at Sirius's place.
"Is your family in any sort of danger?" she asked.
"Hermione, we've been friends for a long time," said Daphne in a tone that was colder than ice. "But between friends and family, I will always pick family. This is none of your business, so kindly keep your nose out of our affairs."
Hermione looked hurt; she'd never been especially close friends with Oleandra and Tracey, but ever since her second year at Hogwarts, whenever she'd have a fight with Harry or Ron, Daphne would always be there for her. Whenever she'd feel lonely or alienated from her fellow Gryffindors, Daphne would always keep her company. They shared all of their classes, so they often studied together in the library and compared notes.
"Sis, we can't pretend like nothing's happening," said Oleandra emphatically. "We have power, so it's our responsibility to use it. Voldemort's everyone's problem, not just ours."
Daphne looked at her resentfully.
"You've changed," she said sullenly. "I used to be able to read you like an open book, but now, I rarely have any idea what's going on through that head of yours. You might not lie any more, but you didn't used to be this dishonest towards your family before!"
Oleandra fought hard to keep her eyebrows from rising in surprise. Her twin sister had actually noticed that she had stopped telling lies of any kind? The nail that sticks out gets hammered down; doing something conspicuous was bound to draw attention, but Oleandra had just stopped lying from one day to the next. The absence of something was much more difficult to notice than the presence of something, but Daphne had still managed to do it…
"Yeah?" said Oleandra, a hint of frustration creeping into her voice. "Well, guess what: people change. But since you're immortal, you might find that concept a bit difficult to understand."
"Oh yeah?" said Daphne furiously. "Well, since you're not going to be around for that long, maybe I just want to keep you from running headlong into a premature death; even if that means I have to physically restrain you to stop you from doing stupid things!"
"Try me," Oleandra sneered. "If you think you're hard enough."
"Stop fighting!" Tracey shouted. "Aren't you supposed to be sisters?"
The bathroom stall's door suddenly exploded outwards, as Daphne seized Tracey and Hermione with her prehensile hair and pushed them out. At the same time, she wound the rest of her hair around Oleandra, weaving a tight cocoon of vines around her.
"Don't bother struggling," said Daphne dully. "I've bound your fingers and your mouth. And Hermione… don't come near us again."
Hermione's mouth open and closed like fish's, but she could not find the right words. She had never intended for this to happen; she'd only wanted a second teacher for her study group…
"Oleandra… Daphne…" Tracey sobbed. "Stop…"
Even with her limbs, hands and mouth sealed, Oleandra was not powerless. She was rather reluctant to draw on the sources of water nearby, as she was the Lady of the Lake, not the Lady of the Toilet Bowl, but things had gone too far already…
Oleandra closed her eyes and called out to the water; she felt the water coursing through Hogwarts's plumbing like veins, searched for its source… The castle drew its water directly from the Black Lake, so doing this was going to be even easier than she had erstwhile thought.
As Daphne strode towards the exit, dragging Oleandra behind her, taps and toilets began rumbling. The water pressure mounted, until the pipes finally reached their breaking points. A deluge of water burst out of every single pipe in the girls' bathroom, except the one that hid the entrance to the Chamber of Secrets.
A column of water slammed into Daphne, causing her to release Oleandra, who quickly got to her feet.
"How?" Daphne simply asked, spitting out mouthfuls of water.
But Oleandra simply clenched her fist in Daphne's direction. Water rushed to the small girl's side, covering her until she was trapped inside a bubble of it. Unable to breathe, Daphne desperately tried swimming her way out, but to her horror, she found that no matter how hard she kicked, she remained firmly in the centre of the bubble.
"Stop it!" Hermione cried. "She'll drown!"
"She won't," said Oleandra, her voice wavering slightly.
She clicked her fingers, and the bubble burst. Daphne dropped to the ground, coughing up water and gasping for air.
"Please try to understand, Daphne," said Oleandra softly. "This is something I have to do."
"Do whatever you want," Daphne said, breathing heavily. "It's not like I can stop you, anyway."
She got to her feet and unsteadily made her way to the exit, before turning around, one last time.
"But whatever happens," she said with finality, "it'll be on you."
And then she threw open the door and walked out, leaving Oleandra, Tracey and Hermione standing in two feet of water. For a while, they stood there in a silence punctuated only by the drip-drip-dripping of water droplets falling from the ceiling to the wet floor below.
"Thank you, Oleandra," said Hermione, the first to break the silence. "I can't imagine how hard of a choice that must have been for you. I'll reach out again within two weeks, and I promise it'll all be worth it."
"It was the only choice to make," Oleandra simply answered.
Hermione nodded, before exiting the bathroom, leaving Oleandra alone with Tracey.
If one ignored the fact that they were in the girls' bathroom and that Oleandra had just had the worst sibling fight in her entire life, the water dripping from the ceiling like rain would have made a romantic moment for the two, but for now, that was the furthest thing from their minds.
"Well, that could have gone better," said Oleandra in a feeble attempt at a joke. "Do you think I've made the right decision, Trace?"
Now that Oleandra had made her bed, she had to lie in it. If other Slytherins learned of this, it would most certainly look bad. But would it lead to her parents' deaths at Voldemort's hands? She had no way of knowing if children's matters would affect the Dark Lord's grand plans for them, and now, it was eating her up from the inside.
"I don't know," said Tracey shakily.
"Do you think I've changed too?" Oleandra asked sadly.
"You're still the same Oleandra I've always known," said Tracey, bravely attempting a smile.
Liar, Oleandra's eyes told her.
"We should go," Oleandra said, matching her smile. "Filch and Mrs. Norris will be here any moment, thanks to the mess I've made. D'you think there are still some sandwiches left in the Great Hall?"