Disclaimer: Sadly, anything you recognise does not belong to me.

Author's Notes: Thank you for your continued interest, the reviews have been both informative and lovely. Write more of them, would you kindly? Also, you recently broke the 1000 views mark, so thank you for that too.
I am considering renaming the fic, in the beginning "Snape Fails" was perfectly apt, but as the story developed it took new and unexpected turns (though it will still be following roughly the same lines, I promise you that Snape will play violin very soon, but for a completely different reason). The plot has been as much of a surprise to me as it has been for the poor, long-suffering characters.

CHAPTER FOUR

Albus Dumbledore stepped out of the flames, and immediately extinguished them. He had no wish to be spied upon by the ministry interloper, the cuckoo in the nest. He strode over to his unconscious colleague. How many times he had met Severus here, injured, bleeding, convulsing, and occasionally crying? Too many, far too many. He was the general, and they both knew that it was a price worth paying. If he wasn't certain, he certainly could not live with himself, constantly throwing the boy he had failed most painfully into the lion's den. Severus accepted it without question; he probably saw it as his fitting punishment for his great mistake. Albus wondered what his own punishment would be for the lives he had given up to the cause.

He staunched the bleeding and delicately healed the fracture in Severus's skull in moments. When satisfied with his work, he incanted "Enervate". Nothing happened. This was not usual; it would seem Harry's accident had done more damage than a fractured skull, which in wizarding terms was almost minor. He cast the familiar diagnostic spells, apart from not waking up it appeared Severus was functioning. This left only one possibility: raw magic poisoning. A burst of unfettered power not directed in a spell could wreak all kinds of havoc, but the phenomenon was very rare.

Everything about Harry was rare: his ability to survive at any cost was as remarkable as it was improbable. He was an impossible boy. Dumbledore pitied him for it. His ability to survive condemned him to the hardest life, a path few would choose to tread. Dumbledore was perhaps the only man alive who truly understood the weight of that burden, having borne a similar one himself. He longed for the day when Voldemort became a distant memory as Grindelwald has, reduced to a notable achievement on Harry's own Chocolate Frog card. That's the problem with people: they don't realise that there is always the same amount of good and evil in the world, all either need is another champion born to bear their burden, and then a new war rages, same as the old war. The people will lock their doors tight, and hope it goes away. The brave, the passionate, the powerful and the Chosen One will head into battle and make it go away. And Albus Dumbledore, the only man alive who truly knows how hard it is to be the bearer of light, would be sending them to battle. No, to the slaughter. Indeed, he already suspected that Harry's death would be not only possible, but necessary. He hoped that it would be another death that he would overcome, but he could not say for certain. However, he knew beyond any doubt that Harry would do it, because it was what had to be done. Ah, if only the wizarding world knew how close it had come to pinning its hopes of salvation on Neville Longbottom!

Dumbledore levitated Severus to his bedchamber, replaced his robes with a nightshirt, cleaned him and laid him in a comfortable position. It was as touching as it was heartbreaking to remember that when instated as a teacher, Severus's first request was that his old four-poster in Slytherin was transported to his rooms. It could have been expanded into a double, but that had never been necessary. Severus was another boy who viewed the castle as his true home, though his time had been far from happy. Albus wondered if the man's current predicament was his fault. Another great mistake of a man who was simultaneously wise and stupid. His failure to curtail the misbehaviour of the Marauders made him at least partly responsible for his turn from the light, though Severus had barely known light. That intense study of dark magic for which he was known could have been fully utilised in the favour of the Order, had he but realised that below a greasy, snarky exterior lay a good heart waiting to shine. Severus believed himself solely to blame for his every woe, he bore that burden every day of his life, he wore it burned into his skin. Severus wore those long robes not just to hide it from others, but to hide it from himself. At least Albus only had to wear his guilt on the inside. If Dumbledore was a better man he would cry every night, but a general cannot afford to mourn his soldiers, only learn from his mistakes. Albus would never stop learning. He saw this son of Hogwarts throw every moment of his life at the fight against Voldemort, and knew it was necessary to allow him to do so, for the greater good. The price of freedom sometimes seemed too high.

Initially, they had decided not to prevent Umbridge's access, as it would only highlight that Severus was more than a teacher. How ironic that Severus was the only teacher in the school she respected, unaware he was the greatest asset in his army! It was time to change that, both to protect his privacy and to ensure that she remained unaware of his malady and its cause. He hoped to restore Severus soon, as a long absence was certain to rouse her suspicion. The ministry's interference was an intrusion he had fully anticipated, but nonetheless it inconvenienced them to an uncomfortable extent.

For now, the best idea seemed to be to cast the Fidelius charm. In the wisdom if its developer, the intended Secret Keeper could not be the caster. Inconvenient, but intelligent. The possibility of a conflict of interest was too great, lest the Secret Keeper concealed a property with malice in mind. Lily's exceptional charms work was more than sufficient to cast it, though it was far beyond the capabilities of your average witch and wizard. If only they had allowed himself or Sirius to be the Secret Keeper, their deaths may have been prevented. Of course, it was common knowledge that if Voldemort decided you must die, you would die. Her last noble act (of many) was the only possible escape of Wizardkind, in his head he was grateful for her sacrifice, and his heart hated him for it. The only thing that separated Albus from becoming Tom Riddle was his capacity for love, and thus his capability of guilt. Had he been different, had he taken the path he so very nearly did, he could have been the despot of Britain, and he would have killed Tom a long time ago. Those who surrounded him believed that he did not use the Dark Arts because he was too noble, but that was not quite true. He did not use them because he feared that he would enjoy it. In a parallel universe, he was most likely the scourge of Wizardkind, the Great Subjugator. Albus pushed this darkness from his mind, and floo-called Filius.

It always amused him that Filius didn't even have to stoop to enter or exit the fireplaces of Hogwarts, in fact he had a good foot of clearance.

"Albus, what's the matter? It's terribly late! Is something wrong?" Filius squeaked anxiously.
"I'm afraid I cannot tell you a great deal," Albus began, "partly because I am unsure myself. It has become necessary to make Severus's quarters safer. I wish to be Secret Keeper, and you are the most suitable to cast the charm."
Flitwick jumped back a little. It was rare for Dumbledore to be uncertain, even rarer for him to concede it so candidly. "Albus, Severus needs to be present to give his permission. It cannot be cast without him giving you the right." Flitwick said this uncertainly, to the Headmaster that fact should be as basic as Wingardium Leviosa, he could not possibly be ignorant.
Albus lowered his head and gravely stated "Severus understands that I always have the right."
Once again, Filius was nonplussed. It was common knowledge (well, common surmisation) among the senior staff that Dumbledore must have some measure of power over Snape, but if it extended to casting such a powerful and precise charm as this it could only mean that he all but owned the Potions Master, and furthermore that he had Severus's full consent. Not begrudging consent, not coercion, Severus was entirely willing for Dumbledore to be his master. Never again would he doubt Severus' loyalty. Voldemort could not use this particular branch of magic, as it required compassion, and if there was one thing everyone knew about He-Who-Must-Not-Be-Named, it was that he lacked it. It was why the belief that he was not human was so widespread.

"Very well, Albus. You know what you're doing." Filius said trustingly, and he and Albus moved to the centre of the room. As the charm was about secrecy, no outward sign of casting was given. Flitwick conjured a stepladder, and they locked eye contact. He took Albus's hands into his own, and began the casting. A particularly taxing bit of magic, as it must be cast without the usual, comfortable conduits. It came from within, and radiated from him in waves of soft blue light. The waves grew in ferocity, washing to the walls of the room and under the doors. The magic became as a tremendous stormy sea, thaumatic discharges crackled from ceiling to floor like lightning, the room becoming almost too bright to bear. The casting was at full strength, and the Oath must be made.

"Albus Percival Wulfric Brian Dumbledore, do you agree to keep the secret of the private quarters of Severus Snape, to seal and conceal it from the enemies of the same?" Filius incanted the familiar words of the Fidelius charm. It is uncommon knowledge that a spell can in fact be effective in any language, but Latin is the best conduit for intent, and the least likely to result in accidental casting by the inexperienced practitioner.
"By proxy on behalf of the subject, I have the permission and trust of Severus Snape to fulfil this role. Let it be written within me, and there let it remain, until my death or its lifting. None shall reach the private quarters of Severus Snape but through me. I swear it. So mote it be." Dumbledore responded in a heartfelt manner. Flitwick repeated the ancient pagan finality: "So mote it be."
This completed the complex spell. There was a sound like the cracking of a whip, the magic which had been emanating from and surrounding them rushed and buried itself in the walls, they knew it had been successful. Severus was safe. However, it must have completely exhausted the tiny professor, skilled as he was, because the stepladder disappeared back into nothingness. Dumbledore immediately caught him, with reflexes a Seeker would envy.
"Thank you, my friend. I have business with Poppy; would you accompany me to the hospital wing?" Dumbledore asked tactfully. It was always a little embarrassing for a wizard to admit he was spent. The Fidelius charm was so demanding that it could put lesser casters in St. Mungo's, but everyone has their pride. Flitwick merely nodded, Albus knew he would barely be out of the fire before Poppy was forcing Ether down their throats to replenish their magic. It had been less taxing on Albus than on Filius, as the bonder must do the majority of the casting.

Had Wormtail intended to betray James and Lily at the time of casting, his own magic would have rebelled against the betrayal and boiled him from within. Everyone believed the Cruciatus Curse to be the most pain it was possible to feel. They were quite wrong. Death by false Fidelius was a far greater agony, and fatal within an hour. Not that it was possible to gain the testimony of its victims; the constant screaming until their throats and lungs exploded from the pressure prevented that.
Equally unknown was the fact that a Secret Keeper who knowingly betrayed the Fidelius after the casting would only know betrayal from then on; would never again have a place to consider home; would never have a true friend, only a master; would never feel love, only contempt, to the day of his death. The life of a traitor was an unenviable catalogue of miseries, the only mercy being that it was usually quite short, ending in murder or suicide.
The Fidelius charm was in a category Dumbledore called grey magic. It could only be cast in complete altruism, but the consequences of duplicity were as brutal as magic gets. Which is saying something, as there have been some truly psychotic, cruel, yet fantastically skilled wizards over the centuries.

Albus gestured to the huge fire, which crackled cheerfully in the grate as though nothing of note had happened that evening: "After you, Filius".