Shock and Awe

Oleandra momentarily froze; she was scared of a lot of things. Maybe the Boggart would turn into a Basilisk? Surely the Boggart wouldn't be able to copy its ocular prowess, right? It wouldn't actually be able to kill anyone, right??

The legless spider that the Boggart had taken the shape of also froze, its eight eyes fixated on Oleandra. Just as she was beginning to relax, it suddenly trembled, before turning into a gigantic serpent coiled around the wardrobe.

"It's the Basilisk!" cried Ron in terror, while Harry shouted something incomprehensible in Parseltongue.

"Go on, face your fears!" encouraged Professor Lupin.

But Oleandra knew better than that. That thing was not the Basilisk, it couldn't have been. Although it rather looked like one, it had two legs, large leather wings, a long dorsal fin, and its eyes were glowing red. Knowledge bubbled up from within, deep inside her psyche; that was no Basilisk, Wyvern or Dragon. That was a Lindwurm!

"Riddi—" began Oleandra, trying to picture tying the serpent monster into a ballon animal.

And then, all hell broke loose. The Lindwurm roared, and a sigil appeared on its forehead. Everyone around Oleandra was either screaming in terror, stampeding over each other to escape the room, or foaming at the mouth and fainting on the spot. 

Not everyone was panicking, though. The Gryffindor Trio, Daphne and Professor Lupin were somehow still holding on, trying to use Riddikulus on the overinflated Boggart.

But Oleandra didn't notice any of this; she had blanked out everything around her. She fell to her knees, clutching her own forehead, barely aware of her surroundings.

She knew this sigil; she had seen it on her very own reflection in the Mirror of Erised!

She knew this feeling; she had felt true terror when she had been powerless, facing the Basilisk!

Oleandra felt as if a stake had been planted into her brain; searing hot pain streaked into eight directions from that singular point, branding her with a new power. And suddenly, the pain went away, leaving nothing but a dull throbbing sensation.

"Ægishjálmur…" whispered Oleandra.

She had finally comprehended the secrets of fear, by being constantly exposed to terror that no child should ever have to face. Ægishjálmur was a sigil formed by combining Elhaz eight times around a single point, offering unparalleled defence. It was known as the Helm of Awe, or the Helm of Terror, because it inspired fear in one's enemies, who the sigil's user could draw strength from.

Oleandra had no doubt this magic would be classified as the Dark Arts, and therefore she resolved herself never to use this magic unless her identity was disguised. She thus turned back to the situation at hand; the Boggart of unusual size.

"Riddikulus!" shouted Oleandra, brandishing her wand.

This didn't do anything in particular, but one had to remember that even non-beings had limits. Just as Dementors would get indigestion after swallowing up too much of a Patronus's Spirit Guardian's positive emotions, so could a Boggart reach its limits. In fact, Boggarts preferred the kind of fright that jump-scares caused, rather than absolute mind-killing terror, which is why they liked to hide in order to surprise their victims. At the very moment that Oleandra cast her spell, the Boggart just happened to have surpassed its capacity, and it exploded like an overfilled balloon, going back from being a non-being to simply being a non.

"Is everyone all right?" Professor Lupin called out shakily. This was not how he had anticipated his first class going. He had even made sure to keep an eye out on Harry to prevent the Boggart from taking Lord Voldemort's form, but obviously he had overlooked something.

Gradually, those who had been affected came back to their senses. Half of the class had made it out of the staffroom, and it would be difficult to track them down in the short term. The luckier ones had been trampled on during the stampede and knocked unconscious, sparing them further trauma. Hours later, a Muggle-Born student would even be found hiding inside a painting, a burst of accidental magic leading him to jump into a painting, Super Mario 64-style.

And that is how Oleandra's first Defense Against the Dark Arts class of the year ended. After all of the affected students were treated on the spot by Madam Pomfrey (making generous use of the Memory Charm as well as copious doses of Calming Draught), Professor Lupin and the Golden Trio came up to her.

"Bloody hell, Oleandra," the still ashen-faced Ron said. "I don't remember the Basilisk having legs and wings, what was that thing?"

"I don't know," Oleandra half-lied. "It must have come out of my imagination."

"If I remember correctly, that should be a Lindworm, or Lindorm. But you couldn't have seen one before," said Professor Lupin thoughtfully. "They're supposed to be extinct. How did such a creature leave such a deep impression on you that it would become your greatest fear?"

"I really don't know," Oleandra said truthfully. As far as she knew, her subconscious must have picked up this information when she had seen the Mirror of Erised, as the Boggart's transformed form had shown up with a sigil on its head.

"You must have seen one," Harry said after hesitating for a while. He was still reluctant to let others know about his gift, but after discussing some things with Professor Dumbledore, he had come to terms with the fact that Parseltongue could be used for good. "When it screamed, I understood what it said."

"What did it say, Harry?" Granger asked curiously.

"It was asking for help," Harry said seriously, looking at Oleandra. "It was begging to be freed."

"Well, this has been quite an ordeal," Daphne said. "Why don't we all go back to get some rest?"

"That would be wise," Professor Lupin nodded. "Well, then. Off you go!"

Oleandra, Daphne and Tracey quickly trotted off to the dungeons, where their common room was located. Incidentally, Draco had been the first out of the door to flee, so he wasn't with them at the moment. Once they were out of sight, Daphne tapped her forehead meaningfully.

"Mind explaining this?"