A/N Written for Hoggywartyxmas on LJ. I've used some Pottermore elements, and Filius's diary. But there are some parts I've written myself, and they wouldn't have been half as decent without the help of my two wonderful betas, Kelly Chambliss and Tetleybag.

May 16th, 1978

I want to write down exactly what I've heard today. Just Severus's story, as verbatim as I can manage. It's a story that needs to be written somewhere. It's a story that needs to be thought about, but right now I can't think properly. I can write it down, however, and that's what I'll do.

"So you want to know about my Death Eater past?" Severus said simply when I had mumbled and stuttered through my awkward questions. How do you ask a man whether he's so much of a war criminal he shouldn't be a Head of House?

"I can understand that. Yes, I do see your point. Can I ask you, though, to keep this information to yourself?"

I blushed and began to speak, but he interrupted me. "And Professor McGonagall, of course. I see why she wouldn't ask herself. Did she tell you?"

Minerva had told me. At the time, all I had heard was that there had been a prank. An injudicious one; an inappropriate one. The perpetrators – Potter, Black, and Lupin – had received a suitable punishment. Business as usual, with those three. But when Minerva asked me to speak with Severus, she told me the full story. How Black had nearly set werewolf-Lupin loose on Severus. How Potter had stopped him – Snape, that is – just in time. How the whole thing was hushed up at the time, to save Lupin. In a way, that made sense. Lupin's condition wasn't his fault; he would have been a victim as much as Severus. What hadn't made sense was the complete hush-up – the lack of acknowledgement of Severus's position. And Minerva told me that she had realised later, much later, that this had been just one incident in years of relentless bullying. Minerva could still barely talk about it, except in terms of bitter self-accusation. And she had asked me to speak to Severus, "for if he says he joined the Death Eaters because of the bullying at Hogwarts, what could I possibly say? It's my fault – I should have realised what was happening."

"I wouldn't use it as an excuse," Severus continued, as if he had read my thoughts. "There is no excuse. It was, however, one of the reasons. Here's what happened.

"For various reasons that aren't pertinent to this story, I was a bit at a loose end after finishing Hogwarts. I had entertained some notions about a possible future; they had come to naught. And one day, about two years after I left school, I happened to meet Regulus Black. He had been in Slytherin, too, a year below me. We exchanged a few polite words, and suddenly Regulus invited me for a drink. As I had nothing better to do, I accepted. I found him a clever and pleasant companion. At some point he began to tell about You-Know-Who. How much he admired him and his ideas.

"Well, I hadn't really paid much attention to politics. I remembered that Potter, Black, and Lupin were very much against him. If anything, that was a recommendation. Now Regulus, who turned out quite likeable, favoured him.

"Regulus told me that You-Know-Who was against the Statute of Secrecy, because it stopped wizards from reaching their full potential. "He is right," Regulus said, with glowing eyes, "we wizards could do so much more – good things, that would benefit us and Muggles alike – if we could live openly."

"At the time, I felt there was much truth in that. I still think wizards might do useful things were it not for the Secrecy laws, but by now I realise that peaceful cohabitation is a utopia. But then I was more naïve and optimistic.

"Regulus asked me to go with him to a meeting that would take place that afternoon. I agreed. I had no other plans, and by then I was sufficiently intrigued to want to examine these new ideas myself.

"I was welcomed most warmly by You-Know-Who. This was, for me, a pleasant and unusual sensation. I did realise, however, that a man trying to build up a large following would welcome people warmly. It was seducing, but I like to think I was not quite seduced.

"Well, I slowly began to share Regulus's enthusiasm for a world in which we didn't have to hide. I went to meetings. I made friends and acquaintances. People began to greet me in the street; I was invited for drinks in a pub, to people's houses, even. I had friends. I had also found a purpose to my life. In due course, I became a marked Death Eater."

Severus paused, and I gathered my courage. "How … did you feel about You-Know-Who's … about the Pureblood thing?" I finally asked.

"There was talk of that, but hardly in our group. You see, by then there was quite a large following. There was a group that was mostly about muscles and mass. They fell for the "Only Pureblood" thing. And there was our group. The … dare I say more intellectual ones? There, You-Know-Who focussed on the better world he wanted to create, first for wizards, but ultimately for everyone.

"I believed that. We all did, but at the time I felt rather smug for my reasons to believe. You see, the others were mesmerized by his words, his charisma. I prided myself on judging acts, not words. On comparing leaders objectively.

"The way I saw it then, Dumbledore spoke a lot about Muggles and Muggle-borns. But when a young Halfblood boy was nearly killed by a Pureblood, what he did was protect the Pureblood. He barely acknowledged the wrong that was done to me. Now, of course, I have a better understanding of Dumbledore's positon – I see his motives for acting the way he did. But at the time, that's how I saw it.

"The Dark Lord, however, spoke about limiting Muggleborn's rights, but what he actually did was welcome a Halfblood boy and make him a trusted ally – I was seen, by everyone, as a high-flyer. A much-valued member of the group.

"For a while I truly believed in that better world. Then I began to hesitate, and I used these facts to convince myself. Then came the time when I knew it was wrong. But I refused to accept that knowledge. I was afraid. Not for my life, not at all. But of losing the only group of friends I had ever had. I knew what loneliness and despair felt like. I had been there. I was afraid to return.

"Then, one day, Regulus came to see me. He was dreadfully upset. It turned out that he, too, had had doubts. He, too, had stayed for the friendship – and for his Pureblood mother. But now he was convinced of the wrongness of it all. He wouldn't tell me what had changed him. It would be dangerous, he said. He needed my help, needed to get away to do something of vital importance. The way he said 'vital' made me realise, suddenly, that there is 'vita' in that word. It was about life. And death, as it turned out.

"I did what he asked, and he got away. He never returned; I can only hope he achieved what he wanted to do before he died. After that, I should have left.

"I didn't.

"I told myself I could do more good from inside, could protect people better from inside.

"I was wrong.

"The second time I tried to influence things, I failed miserably. If I had left sooner, sought help sooner …

"I was a coward. And a Death Eater, yes. I don't blame myself for joining. I truly believed, in my heart of hearts, that I acted for the greater good. But I do blame myself, daily, for staying. I was a coward. I valued friendship, warmth, comfort, above what I knew was right."

That is Severus's story, exactly as he told me. I can't give an opinion now.

In fact, it had taken Filius a long time to form an opinion. And he wasn't quite sure he'd ever reached one – an opinion one could formulate clearly, that is. But he had seen how things had happened. Where Severus had done the right thing, and where he had been abysmally wrong. He had seen the reasons. They weren't excuses – there were no excuses, Severus was right about that. But reasons, yes.

Slowly, Filius re-read the last part of his entry. I was a coward. I valued friendship, warmth, comfort, above what I knew was right.

He had forgotten that Severus had said those precise words. Was there a message in them now? An explanation?

For slowly, friendship had grown between them. And warmth. And comfort. And friendship had grown between Severus and the other Heads, too. How had that begun?

The Monthly Meetings. Yes.

When Filius told Severus about the Monthly Meetings (it had been agreed that he would be the one to help the new Head find his way – come to think of it, that, too, had been a plan of Minerva) Severus had been horrified. No-one had told him socializing was part of the job, he had protested, and he doubted his presence would be required after the business part.

But in spite of his mutterings he had come to their first meeting of the year. And had stayed, mostly silently, occasionally sipping the one glass of Firewhisky that lasted him an evening. And the next morning, he had produced the pitcher of pumpkin juice for the first time. "He'll do very well," Pomona had nodded, and then she had winced. Severus was truly a wizard with hangover potions, but even he couldn't do miracles. The nod had been injudicious.

Severus and he had often spent evenings together. Sometimes they shared the pain of marking. Sometimes they played chess. Sometimes they just sat and talked, of books, of potions and charms, of their travels. Never of personal things. Filius wouldn't have minded, but Severus, after that one talk about his past, carefully avoided the topics and Filius respected his desire for privacy. Had he been right to think of Severus as a younger brother, knowing so little of his private life?

Yes, Filius thought. Severus and he could be quiet together, an underrated gift. They could laugh together and plot together, too. They had even played a prank together, on one memorable occasion. Or that was what Minerva had called it. Severus and Filius preferred to think of it as 'working for the greater good'.

It had happened during the Lockhart year. They had got into the habit of distinguishing the years by the resident DADA teacher. A habit that had worried him when Severus had been appointed. He had feared the jinx. Would they call it The Severus Year, he had thought, and what could happen to Severus that would stop him teaching?

Filius felt an icy trickle down his spine. Not in his wildest imaginations had he ever thought that … He didn't want to think of it, not now while he was wrapping gifts on this beautiful snowy morning. Better to remember the Lockhart Year Prank. Time remembered is grief forgotten.

How had it started?

When Gilderoy had announced his Valentine plans for the students, Filius had hidden his face in his hands. Severus had looked stonily at his plate. A muscle in Minerva's jaw had spoken volumes, and Pomona had lifted her eyes to the enchanted ceiling, from whence had come a bleak February sun, but no help.

As soon as the students had started babbling – like a band of baboons, as Minerva was wont to say – Gilderoy had looked at his stricken colleagues. "And for you good people I have a very special treat, too!" he had beamed. "Just wait and see – after dinner I'll reveal all! You're going to LOVE this!"

Irma had shuddered, Aurora had taken a too-large gulp of hot tea, Minerva had straightened her back even further, Pomona had gasped. And Severus and Filius had looked at each other and exchanged a curt nod. This had to be stopped, and they would be the ones to stop it. The situation demanded clear, decisive, manly action. My office, Filius had mouthed wordlessly, and Severus had nodded again.

Once in the privacy of his office, they had made a plan. Taking into account every contingency. Ensuring a back-up scenario. Leaving room for last-minute improvisation, for every good plan caters for the unforeseen. Then they had executed it, with their usual competence, Filius liked to think. The last detail had been informing Minerva that Gilderoy wouldn't come down to dinner, as he was slightly indisposed. "A mild throat problem; nothing serious," Filius had said. "He just croaks a bit. He'll be as right as rain in the morning. I think we'd better ignore it – attention will only make him show off more. This is truly a case of 'least said, soonest mended'."

It had been a careful mixture: a goblet of reassurance, a morsel of sound psychological insight that Minerva could only agree upon, and a dash of truth. Severus, Potions Master and Slytherin, had added the dash of truth. The one thing they hadn't foreseen was Minerva's exaggerated sense of duty, which had made her check on Gilderoy even though she agreed he was a first-class drama queen who shouldn't be encouraged.

When Severus and Filius had received Minerva's casual little note inviting them to a pre-dinner drink in her rooms, they had gone unsuspectingly. Pomona was already there, grinning behind Minerva's back. And Minerva only had to speak their names to make them realize things had gone pear-shaped.

With a smile, Filius picked up his diary again. What exactly had Minerva said?

February 14th, 1993

"Slightly indisposed, is Gilderoy?" Minerva asked. "Croaking a little? The man can't speak at all – worse, he has the wide mouth and vocal sacs that enable frogs to make those highly distinctive sounds. If Witch Weekly would want to publish a picture of his current smile, they'd need a two-page spread. Not that he is in the mood for smiling. Now, what can have caused that, you think?"

I can recognize a rhetorical question when I see one. Severus has always been a firm believer in saying nothing for as long as possible.

"What, indeed?" Pomona grinned. "I've never heard of such a spell. Must be a very powerful one."

"It is, indeed. The Anura Charm is highly advanced magic, and only few wizards and witches ever managed it," lectured Minerva, in full Professor-mode. "The most famous case was in Germany, in Westphalia, in 1809. A German wizard cast the Charm on his Muggle neighbour with whom he had a quarrel. The German Wizarding authorities repaired the damage and cast Obliviates, but they were not thorough enough, and as a result there is a Muggle tale, written by one of the witnesses, of a frog who was Transfigured into a prince."

I couldn't help beaming. When I first learned that the Sorting Hat had nearly Sorted Minerva into Ravenclaw, I had been highly amused – I am a borderline-Gryffindor myself. Over the years I may have sometimes doubted my own Gryffindorness, but never Minerva's Ravenclaw mind.

"Spoken like the Ravendor you are," I smiled. "Truly Outstanding."

"I couldn't do that Charm myself," Minerva admitted, "It takes a lifelong dedication to Charms. I can only think of one wizard expert enough to manage such perfection."

She let the silence drop.

No-one can let a silence drop like Minerva; I have often admired the technique when she interrogates students. Being on the receiving end is different. I knew what I had to do. I swallowed, made eye contact, and said, taking care neither to blink nor to look away, "I cast it."

"Spoken like a true Gryffinclaw," Minerva said. There was a hint of a smile around her lips and the beginning of laughter in her eyes.

"But there is more," she continued. Pomona rubbed her hands gleefully; the show wasn't over yet.

At some point, Severus and I will get Pomona for this.

"The spell will only work properly if the wizard's wand is held at a 90 degree angle to the larynx of the intended victim," Minerva lectured. I didn't know whether to be surprised at her encyclopaedic knowledge or dismayed at what would come next.

"Now, I knew at once which wizard is brilliant enough to cast it, but that 90 degree angle does puzzle me." Minerva looked from Severus to me and from me to Severus.

Severus bowed slightly, to Minerva and to the inevitable. "I lifted him," he admitted.

"Oh, golly," grinned Pomona. "And with all that coming at him Gilderoy didn't manage a single defensive spell?"

Severus and I sighed simultaneously. Trust Pomona to draw attention to the missing part of our crimes and misdemeanours.

"You can't blame him for that," started Severus.

"He was more or less …" I tried.

"That is to say, one might call him …" Severus offered.

"Perhaps a teensy weensy bit Petrified." Someone had to say it.

"Petrified?" asked Minerva. If I remember correctly, and I usually do, there is no Rule explicitly forbidding teachers to Petrify each other. I would have used that knowledge in our defence, even though Minerva would have argued that there is no such Rule because the idea is anathema to every well-thinking person. But it wasn't necessary.

In the end, Minerva smiled. "I can see how the sight of the two of you doing a Weasley Twin cross-talk act might inspire sufficient dread in a man to give him all the symptoms of Petrification. It will be unfortunate for Lockhart if the world ever finds out, though. What with his impressive résumé and his numerous books."

We both grasped the life-line with both hands. "Most unfortunate," Severus assured her, and, "By all means, let's never mention it to anyone," I suggested.

Pomona started pouring port and sherry, and Severus explained how we wanted to save our colleagues from Lockhart's worst excesses. Not because we expected gratitude; we weren't as foolishly optimistic as that. But because it was The Right Thing to Do. I agreed. I even mentioned the regrettable lack of appreciation of modern Damsels in Distress – I am, after all, borderline Gryffindor and have my fair share of recklessness.

Slowly, Filius closed his diary and put it back in his desk. He set the wards again, cursing the Carrows' presence that made a man cautious even in his very own rooms. Cursing Severus for not putting a stop to them.

But to be annoyed with the man was one thing; to lose faith was something else entirely. He would believe, firmly, that Severus was acting on Albus's instructions, and that there were good reasons not to confide in anyone. And when doubt set in, in the darkest hours of the night, he would convince himself that Albus had insisted on the secrecy, and that Severus hated it as much as they did. But that he, like Albus, felt that utter secrecy was vital to their plans – to whatever plan they had hatched between them.

And once all of this was over – and it would pass; Potter was still free, still out there, doing whatever Albus had told him to do, and the dark would not win – the four of them would start the long job of rebuilding. The four of them would get the school back to normal. They might even try and get it better, this time. There had to be an alternative to Sorting eleven-year-olds, or, at the very least, to fostering enmity between the Houses with House Cups and Quidditch Cups.

Not that Minerva and Severus would take kindly to a change in the Quidditch competition. Their bets on their own Houses were legendary. Actually, for that very reason, suggesting changing the Competition might not be a bad notion. There's nothing like bonding over a mutual enemy, and if Filius were to propose to abolish Quidditch, surely that would get Minerva and Severus on speaking terms and on the same side of an argument? This was an idea worth pondering.

Grinning, Filius reached for the last package. A book stand in ebony inlaid with the palest of woods, in a design of elegant, feather-like curls. Severus was notoriously sober in his personal expenses. Generous in his gifts to others, he seldom bothered to buy anything for himself. Yet he had a keen eye for beauty, and over the years Filius had solved the problem of Christmas gifts by replacing the standard Hogwarts quill holder, ink well, and various other desk items by beautifully-crafted ones. This book stand had been a real find. It was Charmed, so that it would turn the pages of the book on voice command – on Severus's voice alone. He had added that final protective Charm himself. It would be a useful gift for a man who wanted to check a Potions recipe while his hands were dirty from cutting ingredients.

When the war was over, he would tell Severus a thing or two about trusting your nearest and dearest. He would make sure that Severus would climb down from his frosty ivory tower and explain things, apologize, even. Severus might resist, but if all else failed, Filius would use the prerogative of an Older Brother and kick the pup in the backside till stars would spark from his ears. He'd conjure up a footstool if necessary, but by Merlin, he'd make him see sense.

If they all survived. There was only so much even a Ravenclaw going on Gryffindor might do about that – there was no counter-curse to an Avada Kedavra . But one could take into account every contingency. Ensure a back-up scenario. Leaving room for last-minute improvisation, for every good plan caters for the unforeseen.

And one could prepare, too.

Filius looked at his gift. There was a potions book to go with it. And a bookmark, representing the Slytherin Snake on a green background. He consulted the index, carefully selected a chapter, and inserted the thin card. He briefly looked at the chapter title.

Serpentis Antidota .

For now, that would do.