Saturday morning dawned with the clear brilliant light of December, slicing into the room with icy fingers and waking Snape without mercy. He blinked, grimacing, and wondered, not for the first time, why he hadn't chosen to draw the curtains last night.

He swung out of bed, shivering faintly in the chill air of the dungeons and waking fully with the tremor. The view from the windows reminded him of why he didn't draw the curtains as he looked out over a landscape bejewelled by frost, sparkling blue-gold in the dawn.

A thick grey dressing-gown served to take off the chill as Snape padded through into his living room; it was Saturday, no lessons and blessed freedom, but the first order of business would still have to be coffee. He put the coffee pot together quickly, deft hands twisting the water-filled base together with the upper chamber and setting the whole on the stove. He lingered for a moment, warming his hands in the heat radiating from the cast iron, a heat that had yet to defeat the chill of night. Either the house-elves had been slow in restoking the stove that morning, or night had been chillier than expected. No matter, it would warm soon enough and, in the meantime, there was an unexpected pleasure in being wrapped up against the chill that woke him.

It was not until Snape was half-way through the second cup of coffee, settled in a chair by the stove and reading a copy of Ars Alchemica that seemed to have escaped his attention, that the pleasant half-sleepy Saturday morning mood abruptly evaporated.

There was nothing in particular that reminded him but, from one word to the next, between two sips of coffee, dread replaced reverie with a cold greater than anything the night had called up.

Saturday. The staff-old boys Quidditch match. The old boys. Potter.

As if on cue, he heard someone moving about in the laboratory; the walls were too thick to hear through, but a few subtle charms years ago had ensured that he would hear if anyone entered that room whilst he was elsewhere. Hermione had also woken early, it seemed. Miss Granger, he reminded himself. It was safer that way.

So much for peace and solitude. He suppressed an urge to hurl the half-full coffee mug at the wall; it would be a waste of good coffee and, besides, he wasn't entirely certain whether the old wizard down in Somerset who had made the mugs for him was still alive, let alone still working at his surprisingly lucrative Muggle hobby. It would be a shame to lose a good piece of stoneware to a fit of temper over students he didn't even like. Former students. Regardless, they were not worth the mug.

Snape dressed with speed, paying perfunctory attention to the basics - a skincare range for men, he remembered with a snort, splashing water on his face - ridiculous. Buttoned into his Professorial persona, he strode out of his rooms, pausing only to rip the day from Dumbledore's grotesquely cheery Advent calendar. One day less. That was all that could be said about it now.

A couple of long, irritable, strides brought him into the laboratory. The stove here had not yet been lit - the house-elves were not permitted to disturb his working area unless he specifically requested them to do so. Hermione hadn't yet bothered to light it; her breath came in curling translucent clouds, swirling in the dusty sunlight as she bent over the endless pieces of parchment scattered over the table in front of her. A small flame under a nearby cauldron was all the heat in the room.

A flick of a wand and the stove against the wall flared to life; Hermione jumped at the sudden crackling and the crack of expanding metal as a rush of hot air leapt in the chimney.

"Sev - Professor," she said after a moment, staring at him. She visibly gathered herself together. "Good morning," she added, turning back to the parchments.

"Is it?" he muttered under his breath. "You're in here early," he said aloud, moving closer and looking over her shoulder at the scribbling and charts that covered the parchment.

"Umm," she murmured absently. "I needed to check some things over and wanted to get it out of the way. I doubt I'll get much done once the gruesome twosome are here, and with Parvati coming today I wanted to make sure that we were as far ahead as possible."

"Miss Patil is coming today?" asked Snape, recoiling. A pink tinge to his day; all he needed to make it perfect.

"Well, she hasn't said so, but I would be surprised if she didn't." Hermione looked up at him. "She is married to Oliver Wood, after all, and he's certainly going to be here. I assumed she would come with him; it didn't seem an unreasonable assumption."

"No, I suppose not, Miss Granger." Snape frowned as Hermione glared at him. What had he done now? By his standards, that had been a pleasant comment.

"Are you going to help, Professor, or are you simply going to stand there?" came the biting question. Now Snape knew he'd done something, but what ... then memories of chocolate cravings and tears came to him. Perhaps - well, perhaps. He decided that retreat was the wiser option.

"I have duties to see to, Miss Granger. I will, no doubt, see you later." He swept out of the laboratory, removing himself from female hormones; he had had quite enough of those to last a lifetime. He thought he heard Hermione swear as he left but he wasn't certain; given his memories of this particular time of the month, it was entirely plausible.

He prowled the outer reaches of the castle for an hour or so, avoiding the more populated areas, scowling and taking out his bad mood on any hapless students that had the misfortune to be taking shortcuts. No doubt the school legends of the vampiric Potions Master would be augmented but, so long as it eased some of the frustration and irritation, he wasn't remotely concerned. In fact, anything that increased students' dislike and fear of him, and consequently improved their concentration in lessons, could only be for the good.

Eventually even his prowling had to come to end and, as he ran out of obscure corridors, he made his way down towards the castle entrance. Dumbledore would no doubt be looking for him, making sure that he didn't extract himself from the match; worse still, he might send McGonagall or that moron, Queroz, to look for him.

A few staircases - some more co-operative than others - later, Snape had arrived reluctantly in the castle entrance hall. The space was generally busy on a Saturday morning, with the older students coming and going to Hogsmeade and the younger students milling about aimlessly, chattering.

This morning made most Saturday mornings look like an oasis of calm and tranquillity. The chatter assaulted Snape's ears from several staircases above, raising and swooping in a flurry of pitches and volumes, all mingling into an incomprehensible cacophony as Quidditch players and assorted hangers-on all sought to catch up on a decade of news in mere moments. Potter, Weasley, Wood, more Weasleys, and still more inglorious former students, all talking together. He gritted his teeth and strode down.

Snape's arrival in the hall did little to mute the noise; admittedly, the volume fell in his immediate area as he made his way through towards the staffroom corridor on the far side of the hall; he was looking for sanctuary, or as close to it as he could achieve on this day. Behind him followed the usual whispers as former students came to the conclusion that he had not changed. Fools; why should he have changed? It never ceased to amaze him that his students seemed to believe that the fall of Voldemort would have somehow made him into Albus Dumbledore, or something equally unlikely.

It suddenly struck him that Hermione had not, apparently, made that mistake. Perhaps it was their sporadic correspondence over the years or, perhaps, the fact that she knew him rather better than her peers. There was no 'perhaps' about it, he thought whilst he worked his way through the crowd. As he reached the staffroom door, he realised that there was little to be surprised about in the knowledge that Miss Granger had not expected him to have changed.

He had his handle on the door of the room, about to open it, when his luck ran out.

"Professor?"

He had hoped that Hermione was wrong, had hoped neither to see pink nor hear that brittle false brightness.

"Ms Patil," he acknowledged.

"I'd like to see what you've developed so far; you have been working on the line, haven't you?"

She had clearly got over any fears or dislike of talking to him, clearly. Ambition - or perhaps it was greed - overcame many things. A pity. The last thing he wanted was to have this conversation, particularly here, where anyone could hear and now - or later - ask Ms Patil exactly what it was that she had been talking to the dread Professor Snape about.

"I suggest you go down to the Potions area, Ms Patil. Miss Granger is still working in there, I believe. She can answer any questions that you have. Good day."