The Retaliator

As far as she knew, any enchanted artefact's magic would eventually wear off, except in two notable cases: items made out of Goblin-Wrought silver, whose magic would continually grow stronger, and items enhanced with runes, whose magic would remain as long as the runes remained intact.

"What's this one?" asked Oleandra, thoroughly intrigued. 

At first glance, the sword looked like a rusty hunk of metal, but through her special eyes, she could perceive the ancient runes glowing softly like embers. ᛜ. ᛉ. ᛞ. ᚷ. Ingwaz. Elhaz. Dagaz. Gebu.

"Let me see," Percy replied, flipping through his notes. "Ah! I've got it! It's one of the treasures the Irish Ministry of Magic sent for the exposition; its name is Fragarach, also known as the Retaliator, or the Answerer. It belonged to a certain Nuada, it seems."

"Oh, I know that name," Ginny chimed in. "He was the first high king of Ireland; he was from a Wizarding clan known as the Tuatha Dé Danann."

"That's correct," said Percy in astonishment. "I didn't know you were interested in Irish Wizarding history."

"It's connected to a certain interest of mine," explained Ginny. "When I was young— er, when I was younger, I looked into ways to regain limbs lost permanently to dark magic, and I found out about this person: Nuada's epithet is Airgetlám, which means silver hand. See, Nuada lost his hand, which should have disqualified him from kingship, but another Wizard named Dian Cécht created an arm made out of silvery light for him; and thus, the name Silverhand."

"You know an awful lot about this person," Oleandra remarked. "Especially the silver hand thing."

"What about it?" said Ginny defensively. "I happen to think silver hands are cool!"

"Ooh!" said Astoria, sounding thoroughly impressed. "I don't remember any of that from History of Magic!"

"That's because Professor Binns never taught us about him," Daphne replied curtly. "He seems to prefer teaching us about Goblin rebellions and the eccentricities of the various madmen the Wizarding World produced throughout the ages."

Meanwhile, Oleandra was thinking about something. In modern times, ancient Futhark runes were known throughout the magical world, even though almost nobody could use their magic, but things were different back then, when magical communities were more isolated.

It was natural for ancient Norsemen to use these runes, which used the magic of the stars, since they were navigators. But why would they appear on an ancient Irish heirloom? The Irish had their own magical runes; the Ogham, which used the magic of the earth. How very curious…

"Are you almost done?" asked Percy, who was growing slightly displeased from being ignored. "Now then, this sword was given to Nuada by the Wizard Manannán mac Lir, who's known by Muggles as a god of the sea."

'And another mystery solved by me,' thought Oleandra, nodding smugly to herself. 'A so-called god of the sea could have easily sailed to Scandinavia to learn about the stars, since they're used in celestial navigation. He must have learned about Ancient Runes in the process, or something.'

At that moment, a magically enhanced voice rang out through the venue.

"Ladies and gentlemen, please be advised that supper will resume soon," said a woman on stage.

"You should probably head back to your tables," said Percy. "I think your parents are looking for you."

"Thank you for the wonderful presentation, Weatherby," said Ginny. "We learned so many new things."

"You're welc—" Percy began, before saying, "Hey!"

Ginny just snickered and headed back with the Greengrass girls to their table, where new dishes were appearing. Half an hour later, Oleandra was beginning to feel uncomfortably full.

"Just how many courses are there?" Oleandra said. "We've had appetizers, soup and a noodle dish. Then, they called us back for sorbet, and I thought we were done, since they served dessert—"

"It's granita, not sorbet," Daphne corrected her. "It's a palate cleanser, it's supposed to stimulate your appetite for the second main course. Besides, no one asked you to fill up on bread."

"I was hungry!" Oleandra protested. "I didn't think there was going to be so much food!"

"Do you want me to teach you the Vanishing Spell?" Ginny proposed. "You're pretty good at Transfiguration now, right? Vanishing things such as food is very easy. Now, bringing things back from non-being is a little harder, but you should be able to manage it."

"I suppose I can give it a try," said Oleandra. "It'd be a shame to waste such good food."

"Now, there are two ways you can use this spell," Ginny explained. "The first is annihilation; your target will disappear from this world. The second is to transform your target into pure information; you'll be able to bring back the Vanished target. The incantation is: Evanesco."

"Evanesco," said Oleandra, pointing her wand at her half-finished sturgeon. The slice of fish disappeared from her plate, as if it had never even existed.

"…"

"Why can't I stop thinking about sturgeon?" asked Oleandra after a moment. "It's as if the image is seared into my brain."

"Annoying, isn't it?" said Ginny. "If you use the Vanishing Spell this way, you're stuck with a mental image of your target until you release the magic. However, if you wait too long, you'll begin forgetting some details, and eventually you'll no longer be able to bring the Vanished item back. This is why we usually use the Undetectable Extension Charm to help transport things instead of Vanishing them."

"According to Gamp's Law of Elemental Transfiguration," Daphne said, "you can't make food out of nothing. The reverse is also true, you shouldn't be able to make food into nothing. So, where do Vanished things go?"

"Everywhere, and nowhere," said Ginny with a shrug. "Nobody knows, really. Ever lost one sock in a pair, and no matter how hard you searched, you couldn't find the missing sock? It's the same thing."

"That doesn't make any sense," said Oleandra, frowning.

"You'd be surprised at how many things don't make sense," said Ginny with a wide grin. "This is magic we're dealing with, not science!"

Afterwards, a cheese course was served, and Oleandra slipped a few cubes of cheese into a paper napkin in her pouch. And for dessert, she somehow made some room in her stomach for a decadent chocolate cake. Yum.