The door to the archive always creaked on opening; the slower the swing, the more it complained. In hindsight, it was a detail that surprised Snape, remembering the creak, but as he entered it didn't really register with him. He was much more aware of the room being in darkness. Not just unlit, but deep, dense, an almost molasses-like pitch. The archive had never known sunlight and its natural condition was to be cold and black; still…this dark felt solid. He lit his wand.

Shining it before him, the beam fell on typical aspects of the room. The table, shelves, the cupboards and jumble of antiquated treasures. Although unnerved, there was nothing he could see that would give him cause for it. It was just the archive…in darkness.

"Charity?" he said, but the word didn't seem to come out of his mouth quite right. He took a few steps forward into the room. Now that he'd said her name out loud, it occurred to him why he was here; before it had been uncertain. But of course, he was here for Charity. This was where she lived now.

"Are you here?" he croaked and tried hard to moisten his mouth and swallow. He could sense he had goosebumps, that his eyes were wide and his breathing shallow. Something rattled in a distant corner and he swung the beam from his wand towards it… but saw nothing out of the ordinary.

"My love?"

His enquiry was losing focus and purpose. He wasn't alone in the room, all his instincts told him that, but it had none of the feeling he'd had on previous visits. There was no warmth, no welcome, no pleasure in being here.

He took a step forward and felt his boot land on an irregular, slightly spongy surface. Instantly he pointed his wandlight to the floor, and what he saw made his breath catch and his heart chill. At first, he thought they were scraps of paper, but in the still air of the archive, some were fluttering. When he looked closer he realised they were moths. Dead and dying moths, pale, ash-coloured, and, as he lifted the beam of his wand, he saw they were carpeting the entire floor in drifts, like snow.

He gagged and fear closed around him, as though a cloak, and lead-legged he walked forward into the room. His mind screamed at him to leave, but something else propelled him forward, treading on the bodies of moths. "Charity?"

"Here," he heard her say. "Severus? Please?"

He instantly swung his wand in the direction of her voice and a cry caught in his throat. Suddenly, inches away from him was her body, suspended by invisible bonds from the ceiling, upside down. Her clothes were damp, glistening and compressed to her torso as though glued; something liquid and acidic dripped from them. Her hair hung, as it had in Malfoy Manor, streaked with blood. And frozen as he was, he watched as she rotated around, as she must inevitably, and he knew it would be bad even before he saw her face. Heart pounding, he watched and waited what felt like years as her body spun towards him.

A skull. Her face was no more than a skull, faintly stained and tea-coloured as though her flesh had only recently stripped, and her hair was drifting like pale seaweed. But he heard her voice as her skull came to face him. "Severus," it said. "….please…."

And from one of the dismal holes that were her eye sockets came a moth, it climbed out, gripping the bone, its wings beating so fast they blurred, but it didn't fly, it fell, it dropped to the floor and was still.

And Snape's world turned black.

His own strangled cry woke him. He was in his bed, the nightmare like a brand on his brain and he automatically sought out his wand. Seconds later the nearby sconces were lit, and he sat up, breathing hard, absorbing the normality of everything around him. A nightmare, nothing but a nightmare. And yet he also knew it wasn't. Only that evening, in the library, he'd researched ghosts and discovered that some, some like Charity, became abhuman if they failed to find their way. Hell, or some equivalent, steadily came for them, claimed their restive souls, made their limbo torture and they degenerated into grotesque versions of themselves, forever to haunt and punish those they blamed. When he'd read this, Snape had been both startled and appalled, quickly shutting the handwritten volume that Madam Pince had found for him. He left it on the study hall table and swiftly exited the library, pushing the idea out of his head. Charity wouldn't be like that. That would never happen to Charity, she was a scientist. But she was also a witch.

It was a Saturday, and Snape and Servius Apparated outside an empty, broken down barn which was, as intended, devoid of Muggle eyes. Servius immediately bent and dry-retched, and Snape patted his back detachedly. "It will get easier. From Hogwarts to Devon is a long trip for a first time Apparation, by the time you come to learn it for yourself you'll know what to expect."

Servius looked at him as if he were mad.

Snape tugged straight the boy's Slytherin school tie. "Now smarten up, we're late, start walking."

"Why do I even have to come?" grumbled Servius. "I don't know them. I don't care what they name their baby."

They marched through the pretty, village streets of Chudley in the direction of where Snape vaguely recalled the Church to be. He was looking for the steeple: there weren't many villages left where the Church was still the tallest building. Small and Wizarding, Chudley was in reasonable proximity to Malfoy Manor in Wiltshire, and where the Malfoy's were still counted amongst the congregation. It had been some years since Snape had set foot in a Church, and it was classic Malfoy that they could pretend to espouse Christian virtues while hiding their Dark Marks beneath their white sleeves and appropriate the venue for networking and showboating. But everybody deserved the chance to move on. He doubted a Church of England God would smite them when they entered the narthex.

"You were invited. Some things just have to be got through, Servius."

"But this is the first sunny day we've had in weeks! I was going to play footy!"

"There'll be food."

Servius lapsed into barely appeased silence, and before long they had snuck into the back of the Church with a gathering of other guests and kept a low profile as the Christening service ensued.

Afterwards, guests were invited to linger in the Church grounds and enjoy some Malfoy hospitality, with a marquee erected for a buffet, a special nursery area set up for baby Scorpius and a dressed table on which gifts could be placed. Snape realised he hadn't brought a present for Scorpius or the parents, having spent far more time contemplating how he could avoid the occasion rather than how he should attend it. So he skirted the gift table and instead decided to get formalities out of the way by queuing up with Servius to congratulate the parents, grandparents, Godparents and admire the child.

Malfoy was wearing a dove-grey morning suit, his platinum hair drawn back with a bow, and Narcissa wore a silk, sheath dress with bell sleeves and matching pillbox hat, and together they effortlessly outclassed everyone including the parents. When Snape approached, Malfoy grinned broadly and leaned forward to pump his hand. "Severus! Delighted! I'll be honest, I didn't expect to see you, I predicted you'd be busy, so we're feeling particularly honoured you could make it." He glanced at Snape's side, still smiling. "And this must be the young man we've heard so much about?"

Snape introduced Servius. Narcissa watched like a hawk, carefully scanning Servius from the tip of his obstinate cowlick to the toes of his badly polished boots, and in conclusion turned to Snape and said with a cool smile: "He's delightful. So handsome. And I suspect he'll be tall with it."

Servius stared hard at the ground and Snape rather awkwardly said deferential things which Narcissa completely ignored and instead ushered them towards Draco and Astoria. "Dray-dray, darling, come and say hello to Severus and Servius."

It was the first time Snape had laid eyes on Draco in nearly nine years. During the service his view had been blocked and all he'd been able to see was a distant, besuited figure with the iconic white hair. Close up, he found himself re-experiencing his first meeting with Potter, except the shock was harder. This was partly because Snape's memory refused to age Draco more than fourteen, even when Draco had been seventeen. And partly because Draco looked older than twenty-six. He'd been endearing to look at as a boy, but his naturally lean physique was tending more to gaunt, his cheekbones were prominent, his grey eyes slightly hollowed, and he now sported an obvious scar across his brow and down his left temple. He was scarcely able to raise a smile when he came forward with his hand extended.

"Professor," said Draco, shaking Snape's hand briefly and letting it drop. "Father told me you survived and were back at Hogwarts. I can't believe it. You must have a hell of a story."

"Congratulations, Draco," said Snape, forcing himself to be normal. "Firstly on marrying and now you're a father too. I can hardly believe it either."

"Has it been eight, nine years?"

"Nearly nine."

Draco's head tilted a little, the smile faded and there was the faintest of frowns between his brows. "Feels like a lifetime. Thank you for coming."

Snape felt a slightly perturbed frown of his own. He sensed a remoteness in Draco. Dislike was too strong, but distrust might have been closer to the mark.

Draco turned to Servius, who was openly staring. "And this must be your son? Could have knocked me over with a feather, sir. Is it Servius?"

Servius nodded.

"Got your Slytherin tie on. I hope you're a proud serpent?"

"Yes."

"Good at Quidditch?"

"No, sir."

Draco's eyebrows shot up at this. "How come?"

Servius's cheeks turned scarlet and Draco glanced at Snape. Snape lifted one shoulder. "Early days." Behind them, people were still queueing, so Snape dropped a hand on Servius's shoulder and edged him forward a little. "We'll catch up later, Draco, you've many guests. Your lovely mother has invited us to the Manor for Christmas, let's talk properly then."

"Of course," said Draco, and lifted his chin in that way that never changed. But only a trace of a smile could be seen.

After paying brief respects to the pale, exhausted-looking Astoria (Snape had never much cared for her. She'd always come across rather glum and enervated, even as a teenager, a shadow to her sister Daphne who'd Snape would have thought a more likely match), and nodding politely at the ornately dressed, near-bald baby Scorpius, Snape wandered off with Servius to pick at the smorgasbord in the marquee. He'd already slapped Servius's thieving fingers about five times when Malfoy approached him, a flute of champagne in hand.

"Severus! How are things at Hogwarts now term's in full swing? Good roll this year?"

"Yes. Good headcount, over three hundred. Seventy-seven Slytherins."

"Ah, excellent. And I see the Sorting Hat made the best possible choice for Servius." Malfoy once more regarded the boy, narrowing his eyes slightly. "Merlin's beard, Severus, there's no question he's yours."

Servius appeared startled at this and Snape muttered "I didn't doubt it for a minute," but he faltered when he remembered his own insistence on a birth certificate.

"How do you like being a wizard?" Malfoy asked Servius, tapping him lightly on the shoulder with his walking stick. Evidently, he'd asked Ollivander to remake his Snake's Head heirloom.

Servius held Malfoy's eyes quite boldly and then shrugged. "S'alright. But I'm not staying at Hogwarts."

Snape scowled and Malfoy was both surprised and baffled. "No? Where are you going then?"

"I'm going back to my old school. My Ma and Pa said I should try Hogwarts for a year and if I don't like it then I can go home."

"You'd rather be a Muggle?" said Malfoy, astonished.

"What's wrong with Muggles?"

"Servius, enough," said Snape quickly. "Go and…you can have dessert now."

Servius ambled off to a far trestle table and Malfoy turned to Snape with a laugh. "Aren't they charming at that age?"

"He's having some difficulty…adjusting."

"Ah. Just wait till he wins at Quidditch and he'll forget there was ever a life before Hogwarts," said Malfoy smoothly.

Snape moved in a little closer to speak in muted tones. "Speaking of which, I have purchased a broom for him for Christmas and I'm having it sent directly to the Manor. I hope that won't inconvenience you. Could you put it away for me?"

"Certainly, no trouble at all," said Malfoy with an approving nod. "The latest from Diagon I'm assuming?"

"Well…I'm not much of an expert on brooms, but I'm assured it's a popular model and it certainly wasn't cheap. Do you think perhaps Draco could give him some tips?"

"I'll put him up to it, don't worry about a thing. I'll have the elves clear up the circuit on the grounds. What's his position? Don't tell me – Seeker of course!"

"Uh, no…"

Malfoy waited politely a moment, but when Snape wasn't forthcoming he murmured, "Of course, no trouble at all."

They took a few steps away from the worst of the crowd and Snape said, "One other small matter, if I could have a minute."

"By all means!"

"Did any…do you know if any of the old…contingent kept their masks?"

Malfoy's eyebrows raised and then he looked puzzled. "Their DE masks you mean? Why on earth?"

"Just wondering. Perhaps as…souvenirs?"

"Every one that got handed in was destroyed, Severus. Rather a pity. They were very good quality. Illegal to have one now, of course."

"Does anybody make duplicates?"

"Are you after one for yourself?"

"No. Lucius, no I am not interested in having a mask again. I thought I saw one, but it must have been a copy."

Malfoy considered him a moment, then glanced about to ensure they were out of earshot. "I have only seen one of the old rank-and-file in the past year. He didn't have a mask that I recall."

"Who was it?"

Malfoy laughed heartily. "Dear man, you're a Professor now, you can hang up your super-sleuth hat."

Snape studied him a moment while a slideshow of operatives skimmed through his mind's eye, trying to think who was neither dead nor in Azkaban. As the Death Eater downfall had happened largely after Snape had been evacuated, he'd pieced together the rollcall from news reports and scant conversations with escaped operatives he'd later go on to capture. As far as he could gather – and remember – there were only three outstanding, the ones who'd eluded him after discovering he was a Dumbledore agent.

"Never mind. I saw it in a novelty shop in Diagon Alley. Must have been a bad-taste mock-up."

"Doubtless. Now come back and enjoy some champagne."

Not long later, Snape and Servius walked away from the Church back to where they'd Apparated. They'd put in a good appearance, and Servius had started to get agitated and bored so Snape was glad to make his excuses.

They walked in silence down the quaint country lane beneath a row of chestnut trees, their prickly cases littered the path. Snape was deep in thought, when unexpectedly Servius said, "Professor?"

"Dad. Yes?"

"Did you know that man very well?"

"Which man?"

"The one that was the father of the baby."

"Draco. Yes, I knew him well. I've known him since he was a baby himself."

"Oh. What year did he start Hogwarts?"

"Nineteen Ninety-One, something like that. Why?"

"Oh, nothing. It's not right anyway."

"What isn't right?"

"The dates. It's just a heard about a kid at Hogwarts who had like a tattoo in exactly the same place as…as Draco."

Snape looked at Servius sharply. "What tattoo?"

"The one on his wrist. You know, it's like a skull and a snake or something."

Snape was now staring at him. "You saw that? Uh, you saw Draco had a, um, tattoo?"

"Yeah," said Servius nonchalantly, and kicked up a pile of leaves. "He rolled up his sleeves. Probably didn't want to get baby shit on them."

"And you heard about a student at Hogwarts that had the same one?"

"I don't know if it was the same tattoo. It was just in the same place."

"But you don't think it was Draco?"

"No…" Servius started to look a little reserved. "It was a student before Draco was there."

Snape halted and put his hands on his hips, staring laser like at the boy. "What exactly did you hear and who told you?"

"What I told you!" retorted Servius heatedly. "Just that there was some kid who went to Hogwarts like a million years ago who had a tattoo on his wrist, just like, you know, Draco. It's no biggie, okay? Why're you getting all strung up about it?"

Silence hung for a moment, then Snape cleared his throat and started marching fast towards the Disapparation point. "Probably just a coincidence."

"Yeah. Whatever. And Professor?"

"What?"

"You said if I wanted, I could have Mum's research papers. The ones in the folders? Can I have them? I want to read them."

St Andrews Day was fast approaching, a day that McGonagall enjoyed celebrating with Scottish-themed decorations and feast in the Great Hall. Amongst the tartan and Saltire, towering cotton thistles in pots were placed where they could be admired but not touched, and it was the job of first-year Herbology to ensure these biennial plants were in flower.

The Gryffindor Slytherin group was waiting outside Greenhouse Number One for their first morning class, and unusually, Longbottom was not around. As the students sheltered where they could from the frigid wind blowing right off the lake, their hands shoved deep into pockets and scarves wrapped high around the neck and chin, they huddled in small groups talking and glancing about for a sign of their teacher. Amelie, as always, stood alone, apparently oblivious to the slicing cold from her position on an embankment, although plumes of her breath were evident to Servius even from where he stood against the side of the greenhouse.

"On time today, eh, Snape?" came a caustic voice from behind him. He turned to a huddle of Gryffindors and saw Conor McMillan sneering at him.

"What?"

"Can't afford any more points off the Slytherins eh? Have you seen the Hourglasses? Slytherin's coming last now. How many'd you lose, Snape?"

"Fuck off, McMillan."

"How'd you lose them? For being dumber than a sack of shit, or just generally for being a Mugglemunt?"

"Oi! Back off McMillon, you're askin' for it!" yelled Bertram Curteys, a Slytherin Servius hadn't had much to do with and so this surprised him.

"Askin' for what, Bertie?" retorted McMillon loudly. "C'mon then if you're 'ard enough – s'not like Slytherin can get any lower than last. Might as well have a poke, eh?" McMillon stepped free of his group toward Curteys, who was standing with Iona MacGhee and Geraldine Cooper. "Gonna get your ugly snake girlfriends to help you out?"

Curteys, his ears suddenly flaming, boldly approached McMillon and the pair stood chest to chest. Servius started towards them too but Wait for William held him back by the arm.

"Jealous, McMillon?" said Curteys, an inch taller than McMillon and staring him down. "Looking at your Gryffindor slags I wouldn't be surprised. Wouldn't ride one if they begged for it, which they have, but I don't want my dick falling off."

There were gasps from the small nearby group of Gryffindor girls and Flavius Murphy, a handsome Prefect in the making, moved toward the blustering pair and said in a reasonable voice, "Cut it out McMillon, you know the Gryffindor Commandments."

"Did you just hear what he said about the Gryffindor lasses?"

"He's just getting a rise-,"

"McMillon bloody started it!" said Curteys. "He called Snape a Mugglemunt."

"You can't say that!" said Murphy. "His Dad's the ruddy Deputy."

"I think it was his Dad that took half the points off Slytherin," said McMillon with a scathing look at Servius. "It's hard to tell which one's the bigger wanker."

Then William suddenly strode forward and pushed McMillon. "You're the wanker! You – you -," he looked as if he wanted to say more but couldn't think of any words.

"What's this?!" scoffed McMillon. "Sorry, shoulda known we were waiting for you Billy boy. Is it okay with you, Snape, if I teach your little lady what's what?" And with that, McMillon hooked William around the ankle and tripped him. Due to the slight hill they were on, William hit the ground heavily then rolled south.

Servius, blinded, rushed at McMillon and launched himself in frenzy of uncoordinated thumps and punches until they too had hit the ground and rolled in the wet grass. As fists flew, the remaining students encircled them and chanted encouragement, until William got to his feet and grabbed at McMillon to pull him off. In response, Topper Prott pushed William, and then suddenly the majority of boys were in the fray, and half a dozen girls were slapping and pulling hair as well.

"Merlin's beard, what is going on here!?"

It was Longbottom, from nowhere, hauling students up by their collars. "You – and you – up to the Hospital Wing. Watch! You're dripping blood on your jumpers. Who's responsible? Come on! Who started this?"

"Snape sir!" yelled McMillon. "Snape and his girlfriend."

"Fuck you!" hollered Servius. "Prove it!"

Longbottom glanced about, but all the remaining students – Slytherin and Gryffindor alike – were silent and staring at the ground.

"See me after class, Snape. The rest of you – inside, take your stations. Honestly, I was five minutes late!"

It was then that Servius noticed Longbottom's left forearm was roughly bandaged, the binding irregularly laid and sloppy as if he'd done it himself. A stain of red was on the outer side, and the shirt-sleeve that he'd dragged back up his arm was stained with blood as well.

But he didn't have time for a prolonged look: the students trooped into the blessedly heated greenhouse where they stood at their places at the workbenches, and, appearing flustered and irritable as he pulled on his dragon-hide gloves, Longbottom began instruction on thistle-forcing.

An hour later, they all trooped out again, except Servius, who stayed where he was and propped his chin on his hand. He was sore all over now – quite a few of McMillon's thumps had connected – and his bottom lip in particular had a wide, stinging split in it. But at least he hadn't hexed or jinxed – his status as Warlock should be intact.

"Right, Snape," said Longbottom from up at his workbench. "Well I don't know, is there any pleasure in taking points off Slytherin when it's gone into a negative balance?" He was arranging the smaller potted thistles into rows, but paused to look hard at Servius. "Don't try and tell me you didn't start that fight."

"McMillon started it."

"Well naturally; like father like son. Your father made it a point of pride to blame Gryffindor when it was the Slytherins at fault the whole time. He was a bit of a master at arguing black is white."

Servius was simply confused and sat silently.

Longbottom tugged at each finger of his gloves before pulling them off, then turned to fetch his lion-monogrammed Gryffindor Portfolio from his bag. He placed it on the table before him, and as he began turning pages, Servius's eyes were drawn to a glimpse of an image on the exposed inner wrist of his injured arm. The longer he stared the more convinced he became: Longbottom had the same tattoo that Draco had, the one HBP had described in the diary, the one he referred to as a DM. Was it some kind of gang insignia? What on earth did Draco, HBP and Longbottom have in common?

Servius could only see the tattoo in mere snatches: he couldn't confidently say it was the exact image, it was more the location of it that had aroused his suspicions. So he stood and took two steps toward the workbench hoping for a better look.

Longbottom paused and glanced up, instantly alert. "Stay where you are Snape. I'm writing up a report. Give me the names. This will go to the Headmistress and Professor Slughorn."

The pause was perfect, just enough for Servius to have an uninterrupted viewing and Longbottom's eyes followed the lingering gaze. Instantly he turned his wrist over and his thick eyebrows were drawn furiously together. "Yes?" he snapped. "Something on your mind?"

"No, sir."

"Names?" he barked, and when Servius supplied him with a list of Gryffindors and Gryffindors only, he got angrier and slammed the book shut. "Your time is coming," he said in a barely-controlled hush, glaring at Servius. "You. Your contemptible progenitor…it will come to a close."

Servius's eyes grew wide. "Sir? Are you threatening me?"

"Don't be smart. Don't be smart with me."

"But…that sounded like a threat -,"

Longbottom smiled but his eyes were flint. He tilted his head. "Then off you go. Run to Daddy. See if he makes anything of it. He didn't save your mother…why should he make the effort with you?"

At this, Servius's mouth fell open. "What did you just say?"

"Get out. We're done here."

"You don't know anything about my mother!"

"Get out! Now!"

Servius took a few steps backward, trembling with shock and rage, then bolted from the greenhouse. That was the last class he intended to have with Longbottom. Amelie was right – if skipping the class added to his chances of expulsion, then it would be for a good cause.

He ran toward the front door of the castle but then his steps slowed and eventually he came to stop in the courtyard where he stood, clenching and unclenching his fists. He didn't want to go in, he didn't care if he never stepped foot across the great, slate hearth again. Apart from William and Professor Sinistra, he either hated or couldn't care less about every soul in the building. His father had let his mother die, he didn't save her, and if Longbottom knew that then who else did? All the teachers? Sinistra too? The counsellor? Were they all whispering and shaking their heads at him, the child of the murdered woman, son of the man who let her die, who didn't want him?

He half-turned, dazed, and encountered Fisk standing behind him, tail in a slow, ponderous swish. For want of something to do, and unexpectedly sensing comfort, Servius laid a hand on the hound's head. Fisk's tail sped up a little and he licked Servius's hand, then the dog turned and the boy followed.

Fisk led him to Hagrid, busy about his hut garden, carrying pails of indeterminate things. When Servius came into view, forlorn and shivering, one hand on Fisk's head, Hagrid placed his pails down and, standing at full height, looked down his expanse of beard and belly at the boy.

"Alright then, lad? Ain't you got a class you should be in?"

"No. Got a free one."

Hagrid's eyebrows shot up, a little doubtfully. "That so? Righto. So why's Fisk brought you to me then?"

"I dunno. Maybe he thought you needed a hand?"

"Well…I was about to do some digging dreckly but -,"

"No. No digging."

"Want to give them cabbages to the flobberworms?" Hagrid cocked his head towards the pails.

"Fine," said Servius picking one up by its handle and, after searching about amongst various possible haunts that seemed to proliferate around Hagrid's abode, he found the darkened, mouldy wood enclosure with a creaky hatch that, when lifted, caused the creatures inside to shift and slither around against the sudden light. Cringing, Servius upended the bucket and hastily shut the hatch again when sounds of shredding and sucking could be heard.

His mind on was HBP again, grasping for the relief of suppressed emotion, control. He imagined, in his head, was a box, perhaps with a hatch like the flobberworm's cage, and that he could take his anger and fear and loneliness and ball it up, like rubbish paper, and shove it in the box. He could slam the lid down, lock it if necessary, and in time perhaps it would just compost away, like so much flobberworm food. And there was how he would manage it, from now on, when it got too much. It was the best plan he had; so far the only plan.

He wandered back, deep in thought, to the second pail and paused behind Hagrid, who was bent over the business of turning sod. "I thought there were spells for digging," said Servius, it only now occurring to him that he'd never seen Hagrid with a wand.

"Yar, there is, that's true. But this is exercise, ain't it. Good for yer. If yer done with the flobberworms, 'ere's some juicy worms for the fwooper,"

"Erm…actually, still got these cabbages to do. Um, Hagrid, can I ask you something?"

"Ask away, laddie."

"What is a mudblood?"

Hagrid stopped mid-shovel and looked sharply at Servius. "Now where'd you come across that then?"

"Something I read," answered Servius lightly. But he already knew the term was anything but casual. He'd overheard it once or twice in the common room but had largely disregarded it until it had come up in the diary, and in the most spectacular fashion. One day, HBP had not made an entry. The page had been blank, a date in May, Servius remembered. He immediately turned the page and HBP had entered a passage, but short, staccato, in complete contrast to his usual detailed ruminations. He had written that the Ms had used his own spell against him, levicorpus, and that he'd called L a mudblood, and that this seemed particularly dire since L had not forgiven him. To Servius, given that L seemed to be standing around watching with the Ms instead of hexing every single one of them (which is what Servius decided he'd have done, after getting HBP down, and then going back-to-back with him in Warlock mode) he hardly blamed HBP for calling her a name or two. But L had evidently taken it grievously and was unprepared to accept the most grovelling of apologies from HBP, and – having read this far of HBP's diary - Servius knew that it wouldn't have been easy for the boy to have slept outside the Gryffindor common room. Servius thought that if he'd been there, he would have hauled HBP back to Slytherin and given him a talking to. "Plenty of fish in the sea, mate," he would have said. "I don't think she's that much of a friend, no matter what you say about her." The word mudblood, though, had cost HBP dearly.

Hagrid was staring hard, eyes slightly narrowed. "Thass a word we don't use around here."

"I know it's a bad name for someone. But what does it mean?'

Hagrid returned to his digging momentarily and Servius thought he wasn't going to get an explanation. For the normally philosophical, earthy Hagrid to take it so seriously imparted a bit more weight to HBP's crime and Servius waited earnestly.

"A witch or a wizard who was born to non-magical parents. Thass all. Jus' because it's an offensive word, don't mean it must be right. There's no crime in being born to that. An' you don't never use it, you hear? It's hurtful."

"Muggle-borns?"

"Thass right. The same."

"So my mother was a mudblood?"

Hagrid frowned hard at him. "I know wha' yer mean, Servius, but don't be sayin' tha'. Your mother was mighty clever an' wise an' she had a heart like a Hippogriff. She were full of magic. I remember her walkin' about roun' here teachin' hersel' how to do a Patronus. I won't hear of it, you sayin' things like that."

"Is that why she died in the war? Because she was a Muggle-born?"

Hagrid's eyes were like shiny coals beneath his furrowed brow. "She did nothin' wrong. War's a terrible thing, an' it don't make sense."

"Do you know how she died Hagrid?"

There was a sudden, chilling, squealing scream from the Forest, like a tiny tortured child. Servius and Hagrid both glanced in its direction and Fisk barked once, but Hagrid was shaking his shaggy head and turned back to Servius without moving. "S'alright," he said to the wide-eyed boy. "Just a rabbit. Fox 'as got 'im, or a Drop Bear. Now listen: these things about your Mam – you need to talk to your Dad about 'em, not me. Ain't my place, laddie. I'll 'elp you any way I can…but some things is sacred. You talk to your Dad."

Servius scowled at this and jerked up the pail of cabbages, then stomped through the mud back to the flobberworm enclosure. He knew he was closer to the truth of the matter. Snape had given him the folders containing his mother's records and theories (under the promise of death if he lost or ruined any of them, which just proved how little his father understood him) but they were fragmented and didn't make much sense. She had been researching magical genetics, this much he could appreciate, but it was all phrased as theory, not proof: without access to Muggle technology she was frustrated. But what she had written into the textbook was her most important message: the differences between purebloods or Muggle-borns or part-bloods was literally microscopic.

"Hagrid," said Servius, returning to the garden and placing the second empty pail beside the first. "I have another question."

"Righto. Let's hear it."

"Why can't we go near the Whomping Willow?"

"Cos it'll whomp yer o' course!" And Hagrid glanced into the distance at the tree in question, its stringy, leafless branches drooping dejectedly. "Though it's asleep this time o' year so it don't look much."

It was what Servius had hoped to hear. He looked non-committal about it and distracted Hagrid by letting the fwooper out of its cage while he attempted to feed it the worms, and then making his excuses, snuck away directly for the willow while the coast was clear.

There was a tunnel near the Whomping Willow; HBP had described his exploits in it and the role of the willow in guarding it, however the tree was motionless when Servius crept toward it. Small twigs twitched a little, but sparrows and starlings perched on its branches and scolded him without any response at all. As far as Servius could tell, it was as animated as any over-wintering tree.

There was no sign of a tunnel. The grass thereabout was tinged with brown from frost, and damp underfoot, but it was otherwise undisturbed. The entrance had probably been sealed up. "Where is it, HBP?" he muttered, scanning the terrain, looking for anything tell-tale. He knew, geographically, it was unlikely to go straight down but commence at a perpendicular angle and so he concentrated on the face of the hill rather than the flat ground and zeroed in on a conspicuous lumpy section, which were rocks, he discovered, covered in moss and lichen, not grass. After ten minutes of effort, he dislodged a rock at the top of the mound with his hands and then realised he could work much faster if he sat atop the mound and pushed at the remaining rocks with his legs and feet.

Time passed unnoticed while he worked, and the sun rose in the sky and presently he heard a bell ring and then the tell-tale sound of faraway students chatting and laughing. He surmised it was lunchtime and students would be making their way to the Great Hall. The thought of it was loudly seconded by his rumbling stomach, but the idea of going inside where they were drowned out his hunger with an impotent fury. Gritting his teeth, he redoubled his efforts and was soon rewarded with a gap between the rocks, a glimpse of hollow darkness and a gasp of stale air. He was right - this was the entrance to the tunnel: he'd found it. By the time the bell rang again, he'd created enough of a gap between the rocks to slip through, and just as cries of "Servius? Servius where are you?" rang faintly down the hillside, he'd lit his wand and dropped inside.

Snape became aware of Servius's absence as soon as first-year potions were let in. He noticed Wait for William was alone, and as the other students were taking their seats he beckoned him up to the dais and asked in low tones: "Where's Servius?"

"I think with Professor Longbottom, sir," said William anxiously. "He was told to stay behind after class."

"Why?'

William looked at the floor, at the other students, at his hands.

"William?"

"There was a fight sir."

"I see," said Snape briskly, suppressing a sigh. "Is that why you're covered in mud?"

William glanced down as if noticing this for the first time. "Oh. Yes sir."

"And Servius started it I suppose?"

"No sir!" said William hotly. "It was the Gryffindors! McMillon's a wanker!"

Snape glanced over William's head looking for McMillon. "Was he kept back as well?"

"He had to go to the Hospital Wing sir. He was bleeding everywhere."

Snape's brow arched. "This fighting wasn't with wands?"

"Absolutely not sir. Servius wouldn't risk breaking the Oath again."

Snape fought down a smile. "Right. To your desk. He'll join us in a minute. Open your texts, everyone!"

But Servius did not show and mildly concerned, Snape checked the master schedule. Astronomy followed. He would check with Sinistra during recess.

He was saved the trouble by Slughorn, who apprehended him outside the Potions classroom and reported that Servius had now been missing for two periods and none of the students or elves had seen him.

"Longbottom," murmured Snape and Slughorn shoved his glasses up his nose in surprise.

"Neville? What's he got to do with it?"

"Servius was last seen with him. Ask the portraits if they can find him, I'm going to the greenhouse."

His robes billowing behind him as he marched across the Entrance Hall to the main door, Snape found his wand had slipped into his hand with hardly a thought. His subconscious had categorised Longbottom without consulting him. It had to be catastrophic circumstances for Snape to use his wand against a teacher, and yet he didn't put it away: it put him in the right frame of mind - he was looking to confront Longbottom, this targeting of Servius had gone on long enough.

"Severus?"

He had reached the door but turned at his name, turned to the voice. Sinistra. She was coming down the marble staircase and was stepping onto the flagstone floor. "Are you looking for Servius? He wasn't in Astronomy. William thinks he's done a bunk."

Snape's heart had trip-wired at the sight of her – it had been several days now since he'd last seen her (she'd even had his cloak returned to him via a student) - and it pained him to know he'd hurt her. Ever since that evening in her office, he'd wasted an unhealthy number of hours doing little else but replaying events and becoming quite inventive in his speculations about what might have happened if he'd stayed. All sorts of things had been piqued in him as a result of those few intense minutes, and yet he couldn't say that he felt ready for Sinistra, not in the way he had been for Lily or Charity. He couldn't kiss one woman and have another in his head – that wasn't how he worked – but her withdrawal left him bereft and confused.

She was conspicuously demure in her formal teacher attire, hair sleek and secured, her expression carefully neutral as she came towards him.

"Aurora-," he began solemnly, intending to apologise, but she shook her head.

"Don't. Just don't," her voice was soft and she frowned a little, looking to the side of him. "I've dealt with all that. Let's put it behind us."

"But I – I -,"

"No. It was a mistake. I see that now, I shouldn't have confused things. Servius is what matters now."

Snape shook his head a little. "You're wrong, it wasn't a mistake -,"

Then abruptly she glared at him, the furious intensity in her eyes stopping any words in his throat. "I'm humiliated enough, Severus. Let it be!"

He straightened and lowered his lids, retreating immediately. He thought he saw an instant of regret on her features, then she did the same. "Very well," he murmured. "Then yes, Servius. Longbottom was last to see him I believe. I am on my way there now."

She shook her head quickly. "I saw him earlier; Longbottom I mean. He had an injury. He looked like he was heading to the Hospital Wing."

"Longbottom had an injury? I understand there was a fight – surely not -?"

"You think Servius wounded him?! Then could Servius be hurt?"

Snape let his gaze linger on her face for a moment. "I'll find out." Then he redirected towards the staircase.

Within minutes Snape had reached the arched doors to the Hospital only for them to open abruptly before him and Longbottom himself stood there, accompanied by an uneasy Diaphne. Recent medical attention had evidently just been applied, for Longbottom held his left arm awkwardly and the sleeve of his shirt was bloodstained, but he seemed otherwise his normal self. He was in the process of pulling on one of his favoured patterned jumpers and carried on with this in an overtly casual, disinterested way as Snape spoke.

"Longbottom – where is Servius?"

"Severus – always a pleasure to see you."

"Where is Servius?"

"Has Servius gone missing?" asked Diaphne.

"Last seen at Herbology," replied Snape but not looking away from Longbottom. "Answer me. Where is he?"

Longbottom pulled the jumper over his head and attended to his shirt collar. "Well if he's done a runner, it's nothing to do with me. I sent him off to his next class."

"Oh yes? In what kind of condition? Physically or just mentally traumatised? How did you get that injury?"

Longbottom's brow's raised sceptically. "He started a fight, Severus, with the other students. A typical Slytherin manoeuvre to get attention. He really can't afford the House Points can he?"

Snape's eyes narrowed; he stepped close and lifted his wand and placed the tip of it under Longbottom's chin. Longbottom held still and affected nonchalance. "You can't get back at me by picking on Servius," Snape said quietly. "If you want to settle some scores, then you just let me know. You and me. But leave Servius the hell alone."

"Get your wand away from me, Snape," muttered Longbottom, raising his hand and moving the wand aside. "And get a grip. You're losing your mind."

"Professor?" said Diaphne uncertainly. "I – I don't want to report you -,"

Snape scowled at her. "This isn't any concern of yours."

"Of course it is," snapped Longbottom. "I'm unarmed and you're threatening me outside the Hospital Wing. It's a school concern, the way I see it. You and your wayward son are a liability, trying to solve all your problems with fighting. You saw, didn't you Diaphne?"

"Um…" said Diaphne and dropped her eyes.

"Between this and your ridiculous performance at the Halloween Party, I've a serious mind to alert the Headmistress. I warned her she shouldn't take you back. Can't be trusted, I told her."

Snape was glowering. He spoke between clenched teeth. "You don't fool me, Longbottom, not for a second. Why are you really here?"

And there was a split-second of hesitation, Longbottom's eyes widened a fraction, the smug satisfaction faltered, and then were firmly set back in place. "I'm here to teach, Snape. To teach and to lead. I always have."

And with that he stepped past Snape, brusquely hitting his shoulder as he went, and stalked off without a backward glance.

Servius walked through the front door of Hogwarts just after four pm. The sun was setting, a chill had descended, and when he started his run from the Shrieking Shack to Hogwarts, his rucksack bouncing rhythmically if uncomfortably, his breath had fogged. He didn't want to come back through the tunnel – not only had he found it unexpectedly long and dark, it was deeply unsettling - he felt he could travel faster if he were able to set up a steady run. And so with the help of some children who'd come to play in the shack, he'd found the Hogsmeade path back to Hogwarts and set off along it. Now, in his heart of hearts, he was looking forward to a warm dinner, a warm common room, some friends and his bed.

But his reception was anything but warm. It was McGonagall that got the warning from Hagrid as Servius entered the Flying Boar gates, and she was the one waiting at the oaken door as he attempted to open it. The doors had been locked, and there was no chance of a surreptitious entrance. Sheepishly he knocked, and she swung it open and glared at him.

"You've caused quite a ruckus," were her starting words. "Young master Snape, you've got some explaining to do."

Two hours later he was allowed to join the others for dinner. But Snape was livid, Sinistra was wringing her hands, Slughorn was bound to the library for detention every Friday for three weeks and Concetta Cropper had an appointment for Servius the following Monday, Tuesday and Wednesday. And yet none of them discovered where he'd been…he alone knew about the tunnel.

The Crone's Decline potion for McGonagall needed to be prepared that night; there were ingredients that Snape had purchased on his recent trip Diagon Alley that would expire if left unused any longer. After a watchful dinner and seeing Servius under Slughorn's direct supervision, he took to his chamber and started work. He'd hoped that the complexity of the potion would have the effect of distracting him from everything else, as focussed brewing had always done in the past. But instead of falling into a calming, concentrated reverie to the sound of bubbling concoctions and satisfying fumes, his mind was stubborn on its hamster-wheel of unsolvable problems, tugging and pestering for his attention.

He had never brewed this potion before and St Mungo's Apothecary had only released the recipe with great reluctance, having included all kinds of medical indemnities and waivers at the bottom of the scroll that McGonagall had been obliged to accept. When the first batch didn't have the exact colour as prescribed, Snape pondered for a full fifteen minutes on what that might signify and whether a risk could be afforded. He knew his mind hadn't been fully on the job.

Eventually, distrusting himself, he set it aside for a second opinion from Slughorn, then turned off the cauldron burner. He leant on his arms against the wide, oak mixing bench and hung his head, exhausted, frustrated and questioning himself more than he could remember since the last year of the war. Was Longbottom right? Was it a mistake for him to think he could start over?

There was a soft knock on the door, and he glanced up, glassy-eyed. It was getting late into the evening and hadn't expected any visitors. "Who is it?"

"It's Aurora. Can I come in?"

He stood very straight, a thrill of nerves suddenly snapping him to attention. With his wand, he swung the door open and watched with trepidation as she entered and shut the door behind her. She had on her plush winter cloak with the hood pulled up and gave every impression of someone who'd travelled incognito. Once inside, she stopped on the other side of his workbench and dropped the hood back, her eyes on his were wide but reproachful.

"Hello…" said Snape, and the word sounded strange even to him. He seldom said it. He just wasn't sure what words were appropriate under the circumstances.

"I didn't know where you were," she said.

"Oh…," he waved his hand generally over the cauldron and bench. "I'm brewing."

She frowned at him. Then she hung her head back and took a deep breath. "I don't know what I'm doing. I'm…I've gotten all mixed up."

"Did…did you want help with something?"

"Yes, Severus!" she exclaimed but then lowered her voice in effort to sound reasonable. "I – I want us to agree that, that – we'll just work together for Servius's sake? I mean, today shouldn't have happened – you saw Minerva, her patience is running thin, I don't want him to give her grounds for suspending or even expelling him."

"Yes," he said after a moment, staring. "He likes you. We should work together."

She wandered along the length of the bench a little, then paused again to toy with a stirrer. "I'll never be Charity – I mean, I'll never replace her as his mother, but -," she looked up at him, "…but I genuinely care about him and…and I would like to be there for him."

Snape was still staring at her, his breathing quickened a little. "He trusts you. He has few others in his life right now."

"And…everyone needs affection, don't they Severus?" She met his stare. "He seemed to really like it when I…gave him a cuddle the other evening."

She took a few more steps along her side of the bench and Snape took a step as well, keeping level.

"Affection…touch…," he swallowed. "A person can crave it."

"Yes. It's like…it can switch you on…"

She had reached the end of the bench and rounded the edge, coming to face him. Her eyes never left his.

"Sometimes words aren't enough…" muttered Snape, and his words did indeed die away when he saw the hope and longing in her expression.

"Severus - ?" she whispered, half question, half anticipation, and he cut off anything further by crushing his mouth to hers, pulling her body forcibly up against him.

"I'm sorry," he breathed afterward, his lips still lingering on hers. "I don't know what I'm doing either."

Her fingers through his hair, she brought his head down again and they fell back, hitting the bench, her arm knocking over bottles of ingredients.

"This is just for Servius, us working together," she gasped as he ripped free the catch of her cloak to kiss her neck. "We're all he has."

"We should go to my room to discuss it," said Snape, his hands running up the inside of her top, pushing up her bra.

"A meeting, yes! Oh…yes…"

"Indeed, let's have a meeting…" Then they kissed again for several minutes and in several places and Sinistra slid her hands up his back and along his shoulders then pulled away, to blink worriedly at all he buttons on his coat.

"How do I take this off?"

He had a trick, perfected after years of donning and removing the same style of garment. At a certain angle, he could pull down at the collar of the coat and the buttons one by one slipped free, zip-like. She watched, amazed, then leapt in to finish the job. When she threw the coat and cravat aside, they crashed against more bottles and some beakers as well.

But Snape barely noticed. She now had her hands inside his shirt, on his chest, his torso, and it had been months since he'd been physically touched. His skin almost quivered with pleasure, coming awake beneath her fingers, and desire, untrammelled, coursed through his veins. He half-planned to take her to his room, to his bed, but he couldn't quite think straight and things were moving too fast. She had her own top off now and she smelt heavenly, she tasted heavenly where his lips grazed over her, it was intoxicating.

"Up on the table," she muttered, and needing no further encouragement, he hoisted her up and she lay down on her fur-lined cloak, claiming the space and sweeping a few last test-tubes to the floor. In some way he didn't remember, he joined her, only pausing to pull off his shirt while she undid her bra. Then she brought him down into her arms and he kissed her again, slower now, feeling her breasts against him, feeling the heat, her writhing, supple softness, her breath on his neck.

His need was urgent now, all his vitality was gathering in one place and this could not be stopped, and so resting on one elbow he pushed up her skirt to grasp her panties.

"Are we doing this Severus?" she breathed when he started to tug them down. "Are you sure?"

"I am more than sure," he said, meeting her dazed eyes. "I think we're working well together."

With a small smile, she wriggled free of her underwear and helped him unbuckle his trousers. He pushed her skirt up to her waist and nudged her thighs apart, and moments later entered her, hard, and she gave a high yelp, and he felt his heart thundering. He closed his eyes, the pleasure intense and vast, and her moans and sighs were like waves he rode on, her raised hips coaxing him into a rhythm.

He didn't want to come so soon, but his excitement was overpowering and the moment had been so unexpected. As he felt the pressure build, the moment of release rising fast and powerful, in his mind he was with Charity in the bed at Dumbledore's cottage, Charity was arching her back, gripping his Dark Mark and saying his name; he felt the burn on his wrist, the pain, and then along with his involuntary groan, searing through it all like first light on the horizon, came the bliss.