Tver was not some sort of devil. After receiving the Weasley twins' solemn promise, he picked up a Canary Cream with genuine interest.
From the outside, it looked no different from the custard biscuits he usually ate.
But after only a brief glance, he spotted the trick.
"A combination of magic and potions? I have to admit, in the field of pranks, you two are the most talented I've seen."
Human Transfiguration was extremely dangerous. It was not that it could not be attempted, but few wizards could guarantee that once they transformed a human body, it would remain stable when exposed to other spells.
That was the real danger. Even if the initial transformation was safe, any external magical interference could trigger unpredictable chain reactions. It was a fragile kind of magic.
George grinned and exchanged a smug look with Fred.
Using potions as the basis for transformation was much safer. Control the dosage carefully, then use magic to amplify the effect and guide the direction of change. That way, the side effects of pure Transfiguration could be avoided.
"We spent ages researching this," George said proudly. "Most of the past six months, actually."
"And," Fred added, "for safety, we even studied the protective enchantments on your badge to strengthen the canary's defenses after transformation."
"So that explains your recent drop in grades. And why you dismantled my badge."
Tver did not sound angry, only amused. He waved the biscuit at them teasingly before, to the shock of the surrounding students, popping it straight into his mouth.
"Nice flavor. Strong milk taste. Not crisp enough, though. A bit too soft."
He swallowed.
Nothing happened.
The twins stared in disbelief as Tver calmly picked up a second biscuit and began savoring it with narrowed eyes.
George snatched one from the plate, hesitated for half a second, and then shoved it into Fred's open mouth.
"Wait, don't—"
Pop.
Fred instantly turned into a plump yellow canary. He flapped his stubby wings furiously and pecked at George's arm with his tiny beak in outrage.
A minute later, he changed back, leaving only a scatter of feathers on the floor as evidence.
"Seems quite effective," Tver observed with interest.
"But Professor," George asked quickly, "why didn't it work on you?"
"If I don't wish it to, your magic won't affect me," Tver replied lightly.
He could hardly admit that he had quietly neutralized the potion and spell inside the biscuit.
"Still, you can brew the potion yourselves and cast the magic yourselves. But where are you getting the biscuits? I heard you're selling Canary Creams for seven Sickles?"
The moment the conversation shifted to business, George and Fred became unusually serious.
"We've been buying the biscuits from the trolley witch on the Hogwarts Express, Madam Marguerite Mason," George explained. "Before, factoring in the potion costs, seven Sickles barely left any profit."
At that, both of them broke into wide smiles.
"But Madam Mason says that wheat, milk, and things like that have become much cheaper recently."
"The prices are even lower than what it costs her to grow them herself, so she just buys the ingredients from shops to make the biscuits."
"That's why she can sell them to us for much less!"
Seeing how pleased they were, Tver knew that the material dumping he had set in motion was already producing results.
For wizards, this kind of dumping was actually beneficial.
Hardly any wizard made a living growing wheat or running livestock farms. Those were not particularly magical professions to begin with.
Since the imported goods were not produced within the wizarding world, there was no danger of crushing local industries.
"So your production costs mainly come from potion ingredients and purchasing the biscuits themselves?"
For Tver, who had a potions laboratory, a plantation, and access to large amounts of Muggle currency, these were negligible expenses.
For the Weasley twins, who did not yet operate on a large scale, those costs were the main constraint on their profits.
Especially since they could not simply raise the price. In the end, the biscuits were still a prank product.
"That's right. The biscuits themselves aren't too bad. The more we buy, the cheaper they get," George said honestly.
"It's the potion ingredients that are the problem," Fred added. "Production is basically fixed, especially for rare materials. The more you buy, the more expensive they become."
The twins sighed.
Development in this area of the wizarding world had practically stalled. There were only so many wizards who needed those materials, so production never expanded much.
"What if," Tver asked suddenly, "a wizard were willing to supply you with potion ingredients and biscuits at a very low price? Would you consider working with him?"
"How low?" George asked immediately.
Fred frowned.
"Our current price isn't the absolute lowest, but if it goes any lower, it would be at cost. Would any wizard really run a business at a loss?"
Tver took a deep breath.
"I… have a friend. She runs a plantation and a potions laboratory. She can also obtain inexpensive Muggle goods through Gringotts."
"She could even provide you with a shop in…" He paused, deciding Knockturn Alley was not appropriate for a joke shop. "…Diagon Alley."
George and Fred exchanged strange looks.
"This friend of yours… is she…"
"No," Tver said quickly, realizing he had reacted too strongly. "Ahem. It's Madam Primpernelle."
"Madam Primpernelle from the Beautifying Potions shop?" George's eyes lit up.
"Think about it," Tver continued. "You could lower your costs, sell Canary Creams in Diagon Alley, and make far more profit than you ever could at Hogwarts."
"And with steady funds, you could develop even more joke products."
"But why would Madam Primpernelle want to cooperate with us?" Fred asked cautiously. "We're just students."
Tver adjusted his robes.
"As it happens, I am a shareholder in the Beautifying Potions shop. A major shareholder."
"I think your products have great potential. And so do you. So I've decided to invest."
"You should've said that earlier!" George exclaimed in relief.
If it had been a complete stranger, they would have hesitated. But if it was Professor Fawley, they had no such concerns.
After all, he gave out Shield Charm badges every Christmas. There was no need for him to swindle them over such a small profit.
Before they knew it, Tver had already pulled them toward a corner to continue discussing details.
After all, he had originally come to the Great Hall for lunch. The business opportunity had simply been a pleasant coincidence.