Camping out in the Great Hall

The feast turned out to be an utterly painful ordeal for Oleandra, Daphne and Tracey. Pansy's gang had spread rumours about them among the Slytherins. According to her, Oleandra was a pathological liar as well as having delusions of grandeur, Daphne was lovers with Hermione, and Tracey liked to dress up as a dog. Lies! Lies and slander!

Eventually, Draco stepped in to help debunk the nasty rumours. Oleandra really had detention earlier in the day, and Tracey was an upstanding girl, who dressed normally. As far as Draco knew. As for Daphne…

"But, but— she was standing right there," Millicent said dumbly, pointing at Daphne. "And then she hugged the other girl, and they disappeared into thin air."

"Nonsense," said a fifth year Slytherin. "You can't Disapparate inside Hogwarts, it's impossible."

"But what about the Sorting Ceremony last year?" Pansy argued. "She clearly appeared out of nowhere, there's no reason why she shouldn't be able to leave as well."

"But she can't be in two places at once," Draco said matter-of-factly. "Right after breakfast, which is when you said you saw her, she was sitting with me in Arithmancy."

Daphne breathed a sigh of relief. It was a good thing that nobody else apart from her friends knew she also went to Divination and Muggle Studies at the same time, or the jig would have been up.

"But I saw her," insisted Millicent.

"Are you calling me a liar, Bulstrode?" said Draco frostily.

And that was the end of that, as nobody was willing to contradict the young master of the Malfoy famiglia.

After the feast, the Slytherins returned to their common room, but not even ten minutes later, they had been sent back to the Great Hall, for some unexplained reason.

"The teachers and I will be conducting a thorough search of the castle," said Professor Dumbledore, as the children were being caged inside the Great Hall. "For your own safety, you will be sleeping here. The Prefects will be overseeing the entrances to the hall. I am also leaving the Head Boy and Girl in charge. You will report to me directly if anything happens by sending word through one of the ghosts."

And with a wave of his wand, the Great Hall was cleared of the usual four tables, and in their place, hundreds of sleeping bags appeared.

"Don't let the bed bugs bite," he said, before closing the great double doors behind him.

Despite the Head Boy and Girl's attempts to keep everyone calm, the truth about what had just happened had soon spread throughout the Great Hall: the escapee from Azkaban, the mass-murderer Black was on the loose inside Hogwarts, having somehow bypassed the Dementors and the school's wards!

"He must have taken a secret passage," said Oleandra. "I've heard from the Weasley twins that there are loads of them. Filch knows about some of them, but there might still be some hidden ones!"

"It's such a shame that he chose today, of all days," said Draco, shaking his head. "He might have got Potter if he had picked any other day."

"All right, everyone settled in?" shouted Percy Weasley, the Head Boy. "Last call to get in your sleeping bags! No more talking! The lights are going out… now!"

A blanket of darkness descended upon the hall as the candles went out at the same time. Even so, whispers still filled the hall with background noise, making it impossible to fall asleep for light sleepers. For a while, Oleandra simply watched the Great Hall's enchanted ceiling, which exactly reproduced the starry night sky.

"Which star is that?" Tracey whispered, pointing to a particularly bright celestial body. "Is it the North Star?"

Evidently, Oleandra wasn't the only one who couldn't sleep. It was rather hard for the sheltered young ladies to fall asleep with so many boys in such close proximity, after all.

"That's not a star, that's Jupiter," Oleandra whispered back. "It's not twinkling; only stars twinkle."

After a moment of silence, Oleandra found something odd going on with the ceiling.

"I'd never noticed before," she whispered. "The ceiling shows more than you'd see outside."

"What do you mean?" Tracey whispered back.

"You can see some out-of-season constellations on the sides," Oleandra explained. "Normally, you can always see the year-round constellations which are closest to Polaris, the North Star, like Draco and Cassiopeia, plus seasonal constellations."

"Did someone say my name?" said the nearby Draco in a whisper.

"Off to the side, you can make out the constellation of Canis Major, the Greater Dog," said Oleandra, pointing lower down, "even though it shouldn't be late enough in the night to see it yet. See? Sirius is shining particularly brightly, tonight."

"Oh, I found Cassiopeia, it was in hiding in the Milky Way. Kinda looks like the sun rune," commented Tracey. "Sowelo. Isn't it weird to have the sun as a constellation?"

"I've been thinking," said Daphne in a low voice, "the magic of runes, it comes from the stars, doesn't it?"

"As opposed to regular magic, whose power originates from deep within the Earth," completed Oleandra. "The energy generated by the Earth's core and tectonic shifts, transported to the surface by telluric currents in Leylines, or Dragon's Veins, if you prefer. Magical Theory, by Adalbert Waffling."

The Earth itself was the source of most magic, but in truth, every single little thing on the planet generated traces amount of it, at the very least.

Incidentally, Hogwarts had been built on a Leyline nodule, from which the castle drew the magic that maintained all of the castle's enchantments, which meant they would last until the Earth itself stopped spinning.

"Yes, I know, thank you for the exposition," said Daphne, rolling her eyes. Pointing upwards, she continued, "What I was trying to say was that the twenty-four runes account for only a small part of all the stars in the cosmos. Wouldn't it be possible to create new spells with the unused stars, and with other constellations?"

"No. Well, maybe?" said Oleandra. "But it wouldn't be compatible with the way we currently use our magic. Together, the twenty-four runes graven in our souls form a stable whole. Add any more, and the whole thing collapses."

"Then, what if we adapted existing constellations into sigils, using the twenty-four runes as building blocks?" said Daphne, her eyes shining. "For example, the sigil on your forehead. It's not part of the twenty-four runes, isn't it?"

"It's eight times Elhaz. You're right, it could work!" exclaimed Oleandra. "And since existing constellations already have meanings associated with them, it definitely shouldn't be impossible, with a little research!"

"I said, I didn't want to hear any talking!" shouted Percy, waking anyone who had managed to fall asleep. "Greengrass, zip it!"