Oleandra didn't quite know what Malfoy had in mind for Saturday, so she had to stick close to him in case he decided to brag about it loudly, as he usually did. Potter and Granger didn't entirely trust her either, so she was flying blind on that side as well. Oleandra shook her head. That was fine, she didn't actually have to invest too much effort in this endeavour to get in Malfoy's way either. A small price to pay for a favour from Potter, which might come in handy one day or another.
The plan was simple. She had already shown an interest to Malfoy about causing trouble for the Gryffindor trio, so she could easily find an excuse to accompany him on his little mission without arousing suspicion. Then, all she had to do was to drop some magical fireworks purchased from the Weasley twins, attracting Filch's attention.
The only problem with this plan was that it would land her in detention with Malfoy, which wasn't ideal. Luckily, Oleandra had finally discovered Perthro's significance after a few months, and why she hadn't found out earlier. Perthro represented secrecy and concealment, which also explained why its stance was to sit down and curl up into a ball; the rune's use was to hide from others! Combined with other runes, it would produce some interesting effects…
Fast forward to Saturday at half-past eleven, and Oleandra and Malfoy had set off from the Slytherin common room. As they walked silently in the dark towards the astronomy tower, lit only by the lights at the tip of their wands, Oleandra started priming her fireworks and dropping them behind her, like some sort of demented Tom Thumb who would plant explosives instead of bread crumbs. The plan was to blame Peeves for this little prank, there was no use in offending Malfoy if she could help it.
As they reached an intersection, Oleandra dropped off her last firework, which would instantly explode, and in turn light up all the others in a chain reaction.
And explode it did, producing a barrage of loud popping noises and all sorts of colourful magical lights. As the sparks whizzed around, Oleandra grabbed Malfoy's shoulder and hissed, "We're done for! Peeves must have been following us all along!"
A particularly bright flash illuminated Malfoy's horrified mien. Clearly, he hadn't considered the possibility of being caught. He looked into her eyes; the message was clear: run!
They both bolted in different directions, but as soon as Malfoy was out of sight, she stopped in her tracks. Oleandra pulled out a tube of lip gloss and a small mirror from her pouch, and set about drawing runes on her face.
"Perthro, hide me from my enemies. Mannaz, conceal the self."
Oleandra had previously tested this out in the margins of her History of Magic homework, making the piece of parchment promptly disappear from sight. She had to wait an hour past her normal bedtime for the paper to reappear so that she could finish her homework, making her fall asleep in class the next day.
However, in the heat of the action, she had completely forgotten that images reflected in a mirror are flipped. Mannaz didn't matter since that rune was symmetrical, but she had drawn Perthro reversed!
The runes glowed briefly. Satisfied, Oleandra was about to snap shut her mirror, when she noticed something unusual; her facial features were disappearing! Panicked, she was about to wipe off the lip gloss, when her face reappeared. Only, it wasn't her face, but a muggle girl's! She knew that face, she had been jealous of its nose back when she had attended muggle primary education!
"Well, I guess this works just as well," she thought to herself, as she started running back to her dormitory.
As she turned a corner, she ran smack dab into Professor McGonagall, who had already caught Malfoy.
"Another Slytherin wandering in the middle of the night!" she began. "We'll see what Professor Snape has to say about —"
Professor McGonagall paused, her brow creasing, and with a lightning-fast speed pulled out her wand and pointed it at Oleandra, who was caught off guard by such an uncharacteristic movement from what was evidently an elderly woman.
"State your identity," Professor McGonagall said simply. "I know all the first years' faces, but I don't know yours; who are you?"
Malfoy watched in amazement as the young girl slowly dragged her hand across her face in a fluid motion, her features scrambling behind her hand as it went, until finally he could see her face clearly; it was Oleandra!
Oleandra was inwardly grumbling to herself. If it had been Filch, he would never have guessed such magic existed, he would have simply taken down her name, then wondered the next day why the name and face weren't in the register of students!
Professor McGonagall was shocked. At first, she had suspected that a student had been using Polyjuice potion to avoid being identified, and she had been ready to wait the full hour to see which sixth or seventh year would dare to brew such a dangerous potion whose recipe was only found in the library's restricted section. An instant later, she was proven wrong as the student had apparently Transfigured their face.
Professor McGonagall couldn't believe her eyes as Oleandra's scowling face appeared before her. The student who consistently performed the worst in her class had attempted a risky human Transfiguration and succeeded, and wandlessly at that? Had she been hiding her talents? But why would one do such a thing!? There was no benefit in doing so!
"Miss Greengrass!" Professor McGonagall exploded. "Have you listened to a single word I said in class? Human transfiguration is incredibly dangerous, which is why it is only taught to sixth- and seventh-year students, and even then, I only accept those who have achieved 'E's in their O.W.L.'s! You could have ended up permanently disfigured, or worse!"
Oleandra kept her mouth shut. There was no explaining her way out of this one, so the best thing to do was just to shut up and take the punishment, she thought. Well, she was wrong.
"One hundred points off Slytherin, for endangering yourself with improper use of Transfiguration!" shouted Professor McGonagall, absolutely fuming at the profound lack of concern the student in front of her was demonstrating.
"I won't ban you from my class just yet," Professor McGonagall continued, having calmed down a little. "But now that I've seen your talent, I will not let you slack off in my class any more."
"AAAAAAAAAAAAAAAAAAAH!" Oleandra screamed internally.