Snape pushed aside a stack of homework and correspondence on his desk , grimacing at the note from Dumbledore to announce a Staff vs Old Boys Quidditch match shortly before the end of term. A few sheets of paper fluttered to the ground as he moved them. As he picked them up, he recognised Hermione's handwriting - they were his most recent correspondence.

The exchange of letters had been unsettling; in the end he had given in and agreed. It was obvious that Hermione wasn't keen to take no for an answer, and Slytherins were nothing if not pragmatic. It would take longer to convince her that he wouldn't help than it would to simply help her. No matter how loath he was to admit this even to himself, curiosity had also played some part in his decision - not any curiosity to do with Ms Patil, unsurprisingly. The pink paper had told him all he needed to know about how she had developed since leaving school.

No, his curiosity had all to do with Hermione; the handful of letters they had exchanged over the years suggested she had done what most of her classmates were incapable of, and had matured. He had occasionally wondered who the adult Hermione would be, and how they would interact. That - more than anything - had ensured his eventual capitulation. He wondered who he would be, in her presence, now.

He had known from the first letter that he would agree, that she would not take 'no' for an answer at this point, and had worded his letters to ensure that she did not. It would have been uncharacteristic of him to agree too soon though, and Severus Snape was never - almost never - uncharacteristic. It would deprive too many people of their basic security. The sun rose and set; objects were subject to gravity; and he was unpleasant and brusque. It was the natural order of things.

He viewed the forthcoming meeting with Ms Patil with some foreboding; being coerced into things by her was not something he was inclined to repeat too willingly. The last time he had submitted to her entreaties was an event he would rather forget but which was burned into his memory with the force of a reverse-Obliviate: if he could convert the way in which that memory was stored into a charm, he could make a fortune from students cramming knowledge prior to OWLs and NEWTs. Or perhaps not; he thought the memory was almost certainly connected to pain, and it was questionable how much students would be willing to endure for exam results.

Patil hadn't known it was Snape that she was cajoling at the time - still didn't know, for that matter, and there was no way in hell that she was ever going to know. If Hermione hadn't already got a story composed, he would provide her with one to cover the reasons for his involvement. Any story but the truth. He had absolutely no intention of ever letting Parvati Patil become aware of the fact that she had waxed the legs of the dread Potions Professor in her final year at Hogwarts.

The memory was the stuff of nightmares; not the pain particularly - despite what one might imagine, Crucio still outranked it; if not for that, the Death Eaters would have been stonewalled by witches everywhere. It was the sheer ... girlishness of the occasion. There wasn't another word for it, otherwise he would have used it. It had been scant consolation that Hermione was no more enamoured of the "girl's night in", and her doubling up with laughter on realising what he had gone through had been even less consolation. The conversation - for want of a better word - between Lavender Brown and Patil had been excruciating. Boys, more boys, and makeup tips. If it had been his life alone, he would have told them in no uncertain terms who they were dealing with, and hang the bloody consequences. The only reason he had held his tongue was a disinclination to see Hermione become sport for Voldemort; some small measure of respect for Dumbledore's wishes figured in the calculations somewhere, but not particularly highly.

Snape stared out of the window, pulling himself back from memories of a decade ago to stare unseeing into the night sky. Snow had fallen at last in the Highlands, reflecting the near-full moon. The grounds and lake that spread out from the foot of the cliffs which housed the Hogwarts dungeons glittered with the cold, sparkling against the black sky.

Skincare and cosmetics. If that wasn't definitive proof of the existence of irony, Snape wasn't certain what would constitute such proof. Lockhart would be proud of him - if the fool was capable of recollecting anything of his existence.

Snape grimaced - laughter, no matter how scornful, was more than he was prepared to countenance at the moment. He looked down at the table that made up his desk, at the papers scattered across it, wincing at the flash of pink not quite obscured. Somewhere in there... long fingers searched, pushing aside one stack of papers in search of something buried by time and end of term marking.

At last he found what he was looking for; a bundle of parchment an inch thick, covered in the near-illegible scrawled shorthand that he used for his private notes. A pity that the work was incomplete - this would have been the best opportunity he could have been given to release this into the public domain without risk of having his name attached to it.

Not quite skincare, or cosmetics, but still perhaps of interest to Ms Patil. Maybe he could finish it soon... Snape leafed through the notes, checking to see where he had got to with his research, to see whether "finishing it soon" was a remotely realistic idea. The short heading said nothing more than 'Project Hermione' - gross sentimentality, but the notes were almost ten years old in places. He had started work on this as a distraction once he had regained his body: it was something to remember the person he had come to know, and he had intended it as a thank-you, if it had ever been finished. Thank you for returning his body intact and his classes on schedule; for keeping his secrets and for too many other things that he was unwilling to name.

Months of dealing with Muggle mopping-up every four weeks had him searching for a way to deal with the issue that wouldn't offend Hermione's concerns about interrupting her cycle. There was very little research in the wizarding world on the long-term use of potions and charms to stem the flow, as it were. It had taken some time to find Muggle research on the same problems, to determine the problems that had concerned Hermione. None of the side-effects, the consequences, had been anything that couldn't be dealt with by a half-competent mediwitch but, all the same, Snape could see why Hermione might not be entirely convinced about the long-term advisability of such things.

So he had set about devising a potion that would deal with the problem tidily, without the side-effects. But time, and classes, and extra-curricular activities involving Voldemort, meant that spare time was something rare for many years and, somehow, now that it was quieter, other things had filled up that spare time without Snape ever remembering to continue the research. Now though - well, he had the time. The Christmas vacation was coming up, and with it something akin to spare time for a while.

Snape glanced at the small tower of books that constituted his 'unread' pile; it could wait. If it was essential, he had already read it. What was in that pile was interesting, but not urgent - and possibly not even interesting, although he wouldn't know until he started to read.

He got up from the table, stretching slightly as muscles protested that he had sat still for too long. He picked up the mug of cold coffee from the desk, together with his notes, and wandered through into the private laboratory housed in his suite of rooms. He left the research propped on a small stand near the long lab table, to remind himself that this was his vacation project. He flicked through the pages again, making a mental note of the supplies he would need to order from Hogsmeade - or Diagon Alley, in some cases - to continue the research. Most of the ingredients he had to hand, and he preferred to work with readily available items wherever possible: it was rather pointless to try and produce something with a mass-market potential that could only be made from the rarest of ingredients. Nonetheless, it was nearly the end of term and stocks inevitably ran low. He added a mental note to check the classroom stocks as well and re-order those at the same time. Students brought a certain amount of potions ingredients with them at the start of term but, nonetheless, the school still needed an adequate supply for classes and for preparations for the infirmary.

Back in his room, Snape glanced at the clock and debated whether to have more coffee. The pot was barely warm on the stove; the fire was dying slowly into glowing embers. He took that as a signal that he should try and get some sleep.