A/N: Inspired by Snape100's Inanimagus Challenge.
Disclaimer: Everything belongs to J.K. Rowling.

...

Hermione shivered in excitement, her body thrumming with energy. Finally, after reading about it all summer and not daring to try for fear of expulsion for use of underage magic in the presence of muggles, she was about to try one of the most advanced feats of transfiguration. What's more, she was going to do it covertly, illicitly even. She had considered asking Professor McGonagall for permission, guidance and supervision and had even been halfway to knocking on her office door before she halted her fist midair and considered the torturous possibility that her Head of House would say no. Or worse yet, that she wasn't ready. Perish the thought. Hermione Granger knew her capabilities and her limitations. She could do this and so, with a rare mischievous grin, she did.

Severus Snape glided silently through the stacks of Hogwarts' library, seeking sanctuary from the outside world among the aged spines and musty pages of thousands of ancient books. Reading was not necessary, it was enough to simply stand in the presence of knowledge and ideas - imperfect though they may be, he mentally acknowledged with a wry twist of the lips, thinking of all the margin notes he had included in his own personal books…and perhaps one or two library books that had earned him detentions as a schoolboy. There had been many unjust detentions over the course of his school days, but the ones from Madam Pince were always deserved and he had always accepted them proudly, not the least sorry for the corrections and improvements he had made in the literature. Even professorship had not changed his place in her eyes; the librarian glared at him every time he entered her domain and watched him with hawk-like intensity. Trailing a finger down a nameless spine, he smirked.

The sparkle of dust motes caught his eye and he sidled up to the end of the row, standing just out of the sunbeam. A table gleamed warmly in the glow of the setting sun. On it were scattered books with scraps of parchment marking the varied places of whatever had caught a student's interest; one was opened, propped up against another. A sheet of parchment with nearly illegible chicken-scratch was pinned under the corner of a tome and an inkbottle, the bottom of the sheet curling up now that it's owner's arm was no longer pinning it down. Two quills graced the desk – a black one perched carelessly across the sticky opening of the inkbottle, and a brown one lying neatly on one of the only small clear surfaces of the table. A book-bag overflowing with rolls of parchment was on the floor, leaning against a chair's legs. Something about the angle of the chair didn't quite sit right with Severus and he contemplated it a moment, noting that it was neither tucked in to the table nor haphazardly angled as if recently vacated, as most students left their chairs. In fact, it looked to be at just the right distance from the table for someone to be sitting in it, pouring over the books and notes.

Potter, he internally sneered. It had to be him in that ridiculous invisibility cloak, no doubt causing trouble of some sort. "Legilimins," he breathed, searching with his mind for what his eyes could not see. Nothing. If he hadn't peeked in Potter's brain before, the fact that he could find no mind would not have given him ample reason to doubt the boy's presence. As it was, he was intimately aware of the wretched Boy-Who-Lived's cotton fluff between the ears.

The angle of the chair still nagging at him and his curiosity sufficiently piqued, Severus stepped forward into the light and dancing motes, squinting as his pupils took too long to contract. The text on display concerned human transfiguration, namely to inanimate objects and a glance over the titles surrounding it revealed supplementary texts pertaining to transfiguration and human physiology. The corner of his mouth twitched, unsure whether to settle for a smirk or sneer. He had an inkling, but he needed to check to be sure. Sliding two fingers into the end of a scroll poking out of the book-bag on the floor, he gently unrolled it enough to see the handwriting and the topic of discourse. Though the essay was undoubtedly meant for Professor Flitwick, Severus recognized the neat, cramped cursive from many overly long potions essays. The corner of his mouth twitched again and settled smoothly into an amused smirk.

Well, well, Miss Granger, it appears rule-breaking on your part isn't limited to aiding Potter's exploits. In fact, this is positively "…genuine," he purred the last word aloud. His eyes roamed the desk again and focused on the brown quill, the only tidy object glaringly out of place. With long fingers, he stroked the table on either side of the Granger-quill, pondering his response to her rule-breaking. He tapped his fingers around the nub – her feet, perhaps? – allowing them to drift dangerously close before he snatched it up.

Oh, yes. This was definitely the Granger girl, self-transfigured as a quill. He could feel her magic running through the hollow shaft and barbs. A spark of amusement flickered in his dark, tunnel-like eyes and he twirled the feather between thumb and forefinger. Holding it up in the rapidly waning sunlight, he could see gold flecks glittering merrily among the vane and afterfeathers, livening up what, in the shadow of her books, appeared to be dull brown.

His smirk widened marginally into a smile that was notorious for sending students of all ages scurrying for cover. Still pinching the calamus between thumb and forefinger, he lightly stroked the outer edges, feeling the ripple of the barbs and the current of her magic against the pads of his fingers.

"Ten points from Gryffindor," he murmured, "for attempting advanced transfiguration without supervision." He paused, tapping the quill thoughtfully against his chin. "Five points to Gryffindor for being successful." Another pause as he laid the quill back down on the table, "And another five if you manage to transform back successfully." Without waiting to see if she would or, indeed, if she could, he spun on his heel and strode purposefully from the library, making his way to the Great Hall for dinner, eyes still glittering with amusement.

It was a rather flushed and off-kilter Hermione Granger who joined her friends for dinner twenty minutes later, lugging a heavy and overflowing book-bag. When she finally found the courage to glance up at the staff table, her gaze was evenly met over the rim of his goblet as he took a sip of its contents. With the slightest outward tip of his goblet, he silently toasted her and five rubies trickled back into Gryffindor's favor.