The next day, Oleandra parked herself in the stairs in front of the front gate, acting nonchalantly. A line was forming as students streamed in, looking forward to their trip to Hogsmeade to buy candy or joke items, or whatnot.
Oleandra slipped into the line, acting as if she had every right to be there. She looked back, scanning the line for a Witch about her size. Having found one, she quickly turned away and put on a wide-brimmed pointy hat.
"Perthro," she whispered.
Immediately, her presence diminished. At the same time, her features twisted and changed, becoming those of a particularly beautiful third year, which probably wasn't ideal. Finally, she discreetly tapped her clothes with her wand; the green and silver of her robes turned to yellow and black. This was the best she could do with her level of Transfiguration. Perthro could only help her with concealment and misdirection, after all. There was only so much runes could do by themselves, since they were only letters! Only by assembling letters into words, sentences and magical circles would they really show more complexity.
Slowly but surely, the line moved forward, and Oleandra began to see why it was taking so much time; Professor McGonagall and Filch were blocking the way out. The teacher held a scroll, probably listing the names of those who had handed in their forms a little before Halloween.
Finally, it was Oleandra's turn. She hoped Professor McGonagall didn't ask her for her name, because she had no idea what it might possibly be. To her relief, the professor said it out loud for her.
"Miss Pimpernelle," she said slowly, eyeing Oleandra. "I can see you're on the list. Have a nice trip."
Professor McGonagall could tell something was off about that student, but she couldn't quite put her finger on it.
It was only a few minutes later that she would finally realize she had been duped, when the real Miss Pimpernelle showed up with her friends. Why hadn't she noticed, she berated herself. The emblem on that student's robes was Slytherin's snake, only coloured yellow and black! How had she missed something so obvious?
Professor McGonagall instantly ran out of the vestibule, trying to find the student that had just escaped from the castle, but she was too late.
Ever since the Metamorphmagus Nymphadora Tonks had graduated last year, she knew of only one student capable of changing her appearance as easily as she changed her shoes, yet was clumsy enough to forget to change the emblem on their robes after transforming.
"Oleandra Greengrass…" McGonagall murmured, narrowing her eyes.
_
Hogsmeade was the only village in Britain which only housed Wizards. These days, most of the magical community lived alongside their Muggle brethren, taking care to appear as normal as they possibly could! Oleandra had never been to Hogsmeade before, so it was with great curiosity that she observed her surroundings. The buildings took all sorts of impossible shapes, and they were brightly coloured. Since Wizards weren't limited by silly concepts such as gravity, physics, the resistance of materials, construction codes and regulations, annexes and rooms could just be added on as needed, which resulted in the asymmetric and unaesthetic houses Oleandra saw. Load-bearing walls? What are those? Can you eat them? Do they taste good?
As Oleandra wandered down the main street, looking at the vitrines, she felt a wave of relief wash over her. She was finally free of that infernal castle! The distress rune had finally completely gone back to its usual state; she was no longer in mortal peril. With a sigh of relief, she looked at her shopping list, then back at the alluring displays. She shrugged; returning to Hogwarts could wait!
An hour later, Oleandra's pouch was full of bags of chocolate frogs (yummy), Dr Filibuster's Fabulous Wet-Start, No-Heat Fireworks (made for good distractions) and a bunch of potion ingredients. Nothing of note happened to her during the past hour, except maybe for a nice old Witch offering her a frog. It turned out to be a real frog, and not one made of chocolate, so Oleandra set it free in a nearby stream.
Her errand completed, she found herself a tree sufficiently far from prying eyes, and reluctantly tree-ported back to Slytherin's scriptorium, where she found her sister stirring a cauldron over a small fire.
"What took you so long?" Daphne asked without taking her eyes off her cauldron.
Wordlessly, Oleandra offered her a chocolate frog, which Daphne promptly shoved into her mouth. Both sisters quite enjoyed chocolate.
"Careful!" she said as crossly as she could manage with her mouth full. "If the frog jumped in the potion, we'd have to start all over again!"
Oleandra sat in silence, as she watched her sister throw in handfuls of ingredients, and occasionally stir to prevent the bottom of the cauldron from burning.
"So, what d'you think's Slytherin's creature?" she asked, breaking the silence. "The old man had the bloodline of the Basilisk, do you think that might be it?"
"That's what I also used to think, but—" Daphne paused. "Oh, that's right, you weren't there this morning. There's been another victim during the night, Professor Snape told us. It's the annoying kid with the camera. So, my new guess is that it's a Gorgon, who can petrify by sight. It also goes with Slytherin's snake theme. It just fits, you know?"
"Don't its victims turn to stone, though?"
"Stone, petrifaction, I daresay it's all the same."
A silence fell over them again, punctuated by the bubbling of the mixture Daphne was concocting and the crackling of the fire.
"We have to hurry up and obtain the missing ingredients," said Daphne after a while. "Doubtlessly, Granger and her flunkies are up to no good with Moste Potente Potions."
"I see," said Daphne, nodding. "If they steal the ingredients from Professor Snape's cupboard first, he'll be on the lookout for further thefts and it'll be impossible for us to obtain what we need. Also, shouldn't it be Potter and his flunkies?"
Daphne rolled her eyes.