"How can you just jump to conclusions like that?"
Kathoom scoffed. "Well, since you've pieced it all together, fine, I'll come clean. I'm the Half-Blood Prince! Isn't it obvious? Look at me—clearly a blend of a ginger cat and an eagle."
Bruce rolled his eyes at the nonsense. He was now certain.
Snape had to be the Half-Blood Prince.
Otherwise, he wouldn't have reacted so strangely, almost as if seeing a reflection of his own past ideas.
In fact, after that moment, Snape didn't bother him again. Both potions classes passed without further trouble. And once Snape finally dismissed them, the Hufflepuffs filed up the stairs from the dim classroom, all throwing curious looks at Bruce.
They'd been holding back, but now that class was over, they couldn't resist.
"How did you do it?" Justin Finch-Fletchley burst out, eyes bright. "You just answered, and even Snape couldn't say anything!"
Of course, Bruce thought. How could he argue when he'd be denying his own idea?
"Oh, I just tried a few things," Bruce replied smoothly. "Maybe Professor Snape just likes students who think for themselves."
Brushing it off, Bruce moved to head to lunch, only to hear a cold voice behind him.
"Wayne."
He turned to see Snape standing at the end of the hall, draped in his long black robes like a particularly forbidding bat.
The other students scattered instantly, terrified of becoming Snape's next target.
"Yes, Professor?" Bruce asked, cradling his books as he walked over.
Snape's expression was unreadable. "I want a report on Polyjuice Potion. Twelve inches. Due next week."
That's nearly a foot of parchment, Bruce noted. A tall order for a first-year student.
Also…
"Isn't Polyjuice Potion…advanced?" Bruce asked.
"It is," Snape replied, an unpleasant smile tugging at his lips. "Our little Potions prodigy…you're not telling me you can't handle it? And Wayne—don't just regurgitate the textbook. I expect originality."
This was a test.
Bruce immediately recognized the challenge—Snape was probing, trying to gauge if Bruce really had potential.
Kathoom, perched at his shoulder, muttered encouragement. "Wayne! Don't you back down! You're a Gothamite, remember? Just a little paper! Go on, show him!"
Not you too, Bruce thought.
This wasn't our assignment. Knowing this owl, he wouldn't write a single word to help.
But still, he had his pride.
"Don't tell me it's too much to handle," Snape added, his tone mocking.
Despite knowing it was bait, Bruce agreed without hesitation.
The young bat never backed down.
After Bruce accepted, Snape left without another word, leaving him lost in thought.
Kathoom chirped, "Well, he only wants a report! He didn't tell you to actually brew the thing."
Polyjuice was famously difficult.
In The Chamber of Secrets, Hermione had taken half a year to brew hers in the girls' bathroom. The fumes alone had probably left Harry and Ron scarred.
"It's not the extra work," Bruce replied. "I'm just thinking of a way to turn this assignment into something Snape will…never forget."
Kathoom felt a chill. Snape was in for it—young Batman didn't easily forget a slight!
---
The afternoon classes were a breeze in comparison—just Herbology and History of Magic.
The Herbology professor, Sprout, who also happened to be Hufflepuff's Head of House, was a cheerful, plump lady who wore an assortment of herbal sprigs like accessories.
They had Herbology in the greenhouse, and that day's lesson was an introduction to cultivating exotic plants and fungi.
The students followed Professor Sprout's guidance, successfully completing the session.
However, as the other students filed out, Bruce hung back, seeking Professor Sprout's advice.
"You're asking about seepwort?"
Sprout eyed him suspiciously. "Isn't that one of the ingredients for Polyjuice Potion? Wayne, you're not trying to brew it, are you? Brewing Polyjuice without supervision is strictly against school rules!"
"Oh no, Professor Sprout!" Bruce assured her, adopting his best innocent expression. "I just had a question. I heard seepwort can only be harvested during a full moon because at any other time, it has…opposite properties. Is that true?"
Realizing this was purely an academic question, Sprout relaxed, smiling again.
"Oh, that's correct, dear. During a full moon, seepwort is imbued with positive magical properties. But outside of a full moon, it's imbued with negative effects."
"Thank you, Professor!" Bruce nodded politely before leaving, and Kathoom flew after him, already guessing what was on his mind.
"Wow, you've really devoured that Half-Blood Prince book!" he said, gleeful. "You're planning on brewing an alternate version of Polyjuice, aren't you?"
In the Prince's seventh-year textbook, there were numerous notes on enhancing existing potions, including Polyjuice.
The original brew, of course, allowed one to assume the appearance of another person for a time. It had no antidote; one had to wait for the effects to wear off.
This lack of reversal was something the Half-Blood Prince had found intolerable, deeming it an insult to his skill. So he'd poured time and energy into designing a possible counter-potion and jotted his findings down in the book.
But there the trail ended, as if he'd never successfully brewed the new potion.
"The Prince didn't quite succeed," Bruce said thoughtfully. "His recipe required taking a potion in advance that would let you keep your appearance safe from any potion or spell. A preemptive solution, not a true antidote."
He remembered the frustrated scrawl in the Prince's handwriting on the page where he'd written the solution.
"However…" Bruce continued, a glint in his eye. "If Snape had pushed his research a bit further, he might've realized that he'd actually invented an entirely new potion—he'd just need to substitute one ingredient."
The first ingredient in Polyjuice was full-moon-harvested seepwort.
Under a full moon, it had positive magical properties that helped one keep their form.
But if harvested at any other time, seepwort would reverse one's attributes, even…their gender.
Bruce intended to brew this variant—a gender-flipping potion designed to leave Snape with a memorable experience indeed.
Kathoom cackled. "Sounds like you've already thought of the perfect person to sample this!"
Bruce nodded, his thoughts flashing to his target.
They both thought the same thing.
Bruce: Snape.
Kathoom: Harry Potter.
---
T/N: Yep. Definitely the same thing