No one particularly wondered about the miraculous turn Toby Dursley's potions work took for the better after April of her fourth year of school. It was generally concluded that she'd matured over the Easter holidays, or else got a good talking-to from her parents about her formerly abysmal marks.

Neither was true. She was as useless as ever, and she could count on no fingers the times her parents had given her 'a good talking-to.' Add that to the fact that she had misinformed her parents on the grading scale (P, D, and the dreaded T, instead of representing, respectively, 'poor', 'dreadful' and 'troll', meant to the ignorant Dursleys 'prestigious', 'distinguished' and 'transcendent'—although her mother had looked suspiciously on Toby's single 'transcendent' and, in retrospect, she shouldn't have got clever with the 't' and just stuck with 'terrific') and there was no reason she should have showed such a marked improvement.

She had, at length, merely scraped by in Potions marks on the coattails of her more dedicated partner, a good-natured Hufflepuff yearmate with an eagerness to get her hands slimy. Toby found the theory of Potions mildly interesting and the applications very useful; the practicality of it, however, with its newts' eyes and chopped-up slugs and insect bits, a touch too distasteful. And hadn't she walked by an apothecary in Diagon once? In any case, Potions was certainly a superfluous talent: Toby Dursley had been taught nothing if not how to be an avid consumer. Potions could be purchased with little to no effort on her part—no one had ever thought her a Hufflepuff of the 'hardworking' department.

A week into her first term, her owl had arrived with a package from home containing, among many other things, a muggle box of latex gloves. She carried them with her to each and every Potions class and refused to so much as touch the desk without them. It was a good friend she'd made in Lauren Allen, who was more than happy to squelch her fingers around in god-knows-what while Toby gingerly turned pages with gloved hands and tried not to breathe through her nose.

It was when partnered potions became few and far between, and individual work began to count for most everything, that her marks began to take a nose-dive. And it was then, definitely, that Toby regretted the whole 'T means transcendent!' bit of nonsense she'd fed her parents, because a great deal of her Potions work was 'transcendent.'

And then, things about-faced. And Toby had her trusty latex gloves to thank. And Scorpius Malfoy and his unfortunate allergy.

He deserved it, she held obstinately. Well, maybe not the whole 'deadly allergy to latex' (was the prat allergic to everything? They still hadn't figured out what had set off his rash in the Herbology lesson first year and he wasn't allowed in that particular greenhouse.) but she couldn't feel too sorry for him.

He had sprinkled pickled woodlice in her hair and, as far as retaliations went, snapping one of her gloves at him shouldn't have been so bad (in fact, it was only a start, and she had been dredging her mind for ideas when he started to swell up).

He'd ended up fine. And it was mostly an accident. Toby still got detention. Scorpius laughed at her when she snuck up to see him in the hospital wing, so she tossed the homework she'd had Lauren collect for him out the window as she left, ignoring Scorpius' hissed "oh, don't be like that, Toby!"

And she'd even been pondering how a 'sorry about almost accidentally killing you' might have gone over. Well, see if he ever heard it now! And the next time his hands started exploring when they were snogging, she was going to bite him. Or maybe she'd just let her hands start exploring in return; find out just how allergic Scorpius was those latex gloves.

It was in one of the barely used potions labs in the dungeon. Picking dead silkworms out of their cocoons. No magic, no wand and (worst of all) no gloves. They'd been confiscated as a danger to a fellow student.

She'd moaned to herself the whole time, squealing when one of the nasty little bastards wasn't quite dead.

"You know you've done those all wrong." The voice came from nowhere, cool and disdainful.

"Well, I don't particularly care that they're all wrong," Toby snapped back, still bent over the table, knife in hand. "They're all done."

"They're useless, you twit. If you're going to be disturbing my peace in here, you ought to be doing something worthwhile. You used a silver knife. Silver completely ruins the--"

"Well then, it's all completely ruined!" Toby informed him. "I'm done. And who the hell are you?" She squinted into the dim lights (really? Who thought that the dungeons were an adequate potion-brewing setting? Clean, sterile white and lots of autoclaved stainless steel and fluorescent lighting; muggles had the right idea about that. Give her some of that and maybe she'd see what she could do.) trying to make out the speaker

"What am I, you mean." The voice had taken a subtle turn for the sullen. "I'm a portrait."

"Oh." There was a painting in the room—a big one that made it look like the room was twice the size it was, for it was a perfect mirror of the lab in oil paint. She didn't see anyone in it. Toby considered for a minute, grimacing as she picked a bit of something-or-other from under her fingernail. "Well, then, who are you? Portraits usually imply people, but maybe you're a particularly talkative cauldron with some kind of wannabe complex."

There was a long pause and then, with no small amount of irony in the tone, he answered, "The half-blood prince."

"Oh, clever," Toby said flatly, looking up from her ruined nails. "Maybe I should think of something pithy like that. 'Mudblood Madam,' how's that sound?"

The half-blood prince was quiet. "People still use that word?" he asked, very, very quietly.

"A few. Not been called one to my face, but it gets whispered, I think," Toby admitted, shrugging her shoulders. "What do you expect? Something that ugly doesn't go away."

Another long silence followed; Toby figured the half-blood prince, whatever or whoever he was, had gone and she began to pack her things.

"Don't call yourself that. It's too ugly for you." The voice was still out of nowhere, and there was a strange, familiar inflection on the 'you'.

"Just for me?" Toby said, feeling contrary. Another long pause.

"No, it's an unbecoming word for anyone," he said after the moment, with the grim solemnity of something dearly paid for.

"Well, I'm glad you feel that way. Later," she said, hoisting her bag onto her shoulder, sweeping out the sheet of long golden hair from under it and waving a blind hand at the empty canvas in farewell.

"You must be terrible at Potions," the voice said, quickly, a transparent attempt to stay her.

"Eh," she said with a wiggly sort of 'so-so' hand movement. "I manage."

"You could do well. If you come back, I'll help you."

Toby was skeptical, suspicious. "Why would you do that? What's in it for you?"

"If you must know, I was a teacher, and I quite miss it. Are you coming back?"

"Maybe."

She went back two weeks later, after receiving another 'transcendent' on a Potions assignment. "Hello, you still in here?" she yelled, waving about a heavily marked-up essay. "I'm pants at Potions and I hate touching anything nasty. Can you fix that?" she asked the empty painting.

"I can't fix anything. And I can't help lazy idiots." The half-blood prince was obviously in a strop about her extended absence.

Toby persisted, her hands on her hips. "Well, good, because I'm only half of that."

"So you're a hardworking idiot. Forgive me, I'd forgotten that yellow and black on your tie."

"No, I'm a lazy savant," Toby snapped. "Look, if that's how you want it, fine, I won't come back." She turned on her heel, entirely prepared to make good on her threat, when he stopped her.

"You did bring your book with you?" he asked, condescension dripping from his voice.

She stalled. "Yes?" she asked, still not quite trusting the direction the conversation had taken.

"Well, sit down and get it out. I have some notes you need to add in the margins. I trust a lazy savant can manage to overcome her squeamishness to follow simple directions, yes?"

Toby nodded slowly, doing as she was told.

No one thought to ask why Toby Dursley's marks improved so dramatically. Her friends often complained about her seemingly intuitive, newfound talent.

"You must be cheating, Toby, no way," Albus Severus accused, looking over her shoulder at her evaluation slip from the last practical exam. Toby smiled smugly as Rose looked on, stricken—her mark was a point lower than Toby's perfection.

"Yes," Rose agreed, a little snappier than normal; a Weasley temper combined with Hermione's thirst for perfection made her quite an ungraceful loser. "Cheater," Rose huffed; that was the greatest, most blasphemous insult she had to bestow.

"Seriously, how are you doing it?" Albus asked after Rose had flounced off in disapproval. "I won't tell her."

"The angel of potions; he sings to me in the dark," Toby deadpanned, rolling her eyes and shoving the parchment into her Louis Vuitton blue jean tote bag. "I can be smart." At Albus' skeptic look, she added, shrugging, "If I really want to."

Toby Dursley managed through her Hogwarts years with the best marks anyone had seen since the likes of Lily Potter—that must be it, most concluded, drawing more lines between Toby Dursley and her great-aunt, again noting the uncanny similarities in their looks, which grew more pronounced as Toby grew older. That's the talent in the blood, it was generally decided. Must be genetic.

She failed exactly one examination after that detention in the abandoned dungeon laboratory. A hair-growth potion in her sixth year failed utterly, despite the carefully noted (although rather more numerous than usual) changes she noted in her textbook, just like her 'half-blood' mentor—still unseen—had dictated. When she went to test her potion, absolutely nothing happened. The professor's mouth had dropped open unattractively; he had since learned to count on her for a perfect example.

Three weeks later, though, it became obvious that the potion had not been the dud that Toby had so angrily lambasted the ever-invisible Half-blood Prince for during her next extracurricular lesson. A glint of red near the roots of her hair became more obviously dark auburn against the beautiful, silky, natural golden blonde Toby was so proud of.

Toby Dursley's hair, to her great fury, grew in brilliantly and immutably auburn for the rest of her life, the exact same shade of red that Severus Snape had once thought so perfectly beautiful on Lily Evans.

I'm still on holiday, but this has been chilling unedited on my harddrive for a few days. I fixed it up during a thunderstorm today when I was having a mini-block on Hestia and Walden, and the traitorous wifi connection I have at the beach house here is cooperating for the moment, so I decided to upload it! Hope this satisfies everyone who's been waiting; it's been nearly a year since I published this fic, and this chapter was the second that I envisioned after I came up with Toby as a character. It was, however, ungodly hard to write. I feel really uncomfortable writing Snape, especially with this character, looking as much like Lily as I have her. I couldn't get the balance between snark and desperate affection right. Let me know how I've done, please?