"I know of that curse," said the witch in one of the oldest, dustiest paintings.

"You do, Hildegard? Why haven't you said anything?

The plump witch ducked her head. "It's not something I like to remember, tied as it is to our darkest hour."

Sherlock narrowed his eyes at her. "Darkest hour?"

"Do you think dark wizards have only arisen in your own lifetime, sir? I assure you, we had them as well, and they didn't namby-pamby about with merely inflicting pain or causing instant death. No, they liked their victims to suffer."

Dumbledore's brow was creased now, and his face looked unusually solemn as he asked, "How have we never heard of this?"

"Because, Dumbledore, we weren't fools. You think there are only three forbidden curses? Oh, no, there were four—but we managed to stamp all knowledge of the other one from existence—or thought we had. Bad as the other three are, that curse was even worse. Too dangerous, too evil to risk being passed on." She shuddered hard enough almost to shake her frame. "It turned a witch or wizard into a Muggle, effectively banishing them from civilized society, leaving them crippled and useless … a horrible spell."

"Was there a cure?" one of the other portraits asked, for which Sherlock was almost grateful. If there were a way to cure John's … malady … that would be good, wouldn't it? Good for John, at least? Restoring the life, the skills he had lost all those years ago? Because it would be selfish of him not to want that for his friend, wouldn't it? Even though it would probably mean John would leave?

But the faded witch was shaking her head. "We never found one, Snape. We just resigned ourselves to taking care of the … the afflicted … and burying all knowledge of the curse."

"Except you didn't, did you?" the long-haired, black-clad wizard in the portrait asked from his place at Dumbledore's right hand. "It seems that someone found out and Mr Watson paid the price … not that anybody seems to have cared—not even him. Reckless Gryffindor that he was, he probably thought he could just ignore it, that it would fix itself, the idiot. Never gave a thought that it might be used against the rest of us, that he should maybe tell someone…"

Sherlock found himself on his feet. "It's Dr Watson, and in fact, he did tell someone, but his information was overlooked or forgotten in the aftermath of the battle. That, or someone deliberately hid the intelligence, I don't know. Do not blame John, though, for being the victim of an attack, nor for his subsequent attempt at creating a new life for himself—one in which, I might remind you, he again risked himself to save lives in battle."

The man in the painting sneered. "You're eager to leap to his defence, but what do you know of magic … or its loss? You're just a Muggle."

Sherlock tilted his head, examining the painted image in front of him. "You grew up as a Muggle, though, didn't you? You believe yourself to be unusually enlightened as regards the non-magical population, but in fact your unhappy childhood colours your judgement more than these others who lived in ignorance of Muggles. You think yourself so superior, sneering down from your frame at me, at John, at everyone you see in this office, no doubt. It's all in your face, in your posture. You suffered, I can see that, but you are not the only one.

"It seems to me," Sherlock continued, pacing the floor, "That you understand John's sacrifice all too well. You gave up a great deal to do what was right, but you let it embitter you. And so you are looking at John—a man who has lost just as much, yet has kept his honour, his charity, and his sense of humour intact—and thinking less of him for it. As if his resilience somehow lessens his suffering."

There was a shocked silence as all the portraits who could, stared between him and Snape. Sherlock fully expected a biting reply—he could tell that in many ways the man was like him. Attacked, he would strike back, without mercy.

Which is why he was so surprised when the man shrugged his black-clad shoulders and said, "I've never been good at forgiveness. Charity of spirit is not exactly … I suppose if Mr … Doctor Watson has recovered from his … injury … enough to still want to do good for the rest of mankind, I can't think less of him for that." He looked pensive for a moment, but then his face tightened and he added, mouth twisting, "But don't think for a minute that his own sacrifices compare to mine."

Sherlock waved a hand. "Oh, no. I'm quite sure being crippled in battle and losing an entire world, all your friends, everything you've trained for not once but twice doesn't compare."

Dumbledore's portrait spoke now, quickly. "In my experience, sacrifice isn't measured by the loss, but by the way with which it is dealt, and I can assure you that Severus exceeded expectations. This is not a contest—and if it were, I can also say without fear of denial that all of us here have our own stories to tell. Personally, though, I would rather continue to explore this curse that Hildegard has remembered, to see if we can't find a cure."

Hildegard's image shook her head. "No, I'm sorry. To explore the possibility of a cure, you would need to know how the curse works, and that is not something that I can tell you. Those few of us who knew were bound by a wizard's vow, and it's not possible for me to tell you anything other than that eight hundred years ago, such a thing existed."

Sherlock glared at her. "So you would consign my friend to a life without magic with no means of appeal?"

She looked down at him sympathetically. (How had he ended up being pitied by a layer of paint?) "It seems that he already has, sir, and that he has made the best of it in a truly heroic fashion. I regret that there's nothing else I can do, but as I said, the best wizards of the age were unable to find a cure."

Sherlock rolled his eyes—and what did a person from eight centuries ago know about scientific method? Who knew what new discoveries had been found since then? For that matter, they had no way of knowing that the curse that had affected John was in fact the same one—what if it had a similar effect but an entirely different foundation?

He was surprised to hear the long-haired man next to Dumbledore scoffing, too. "Oh, please, as if we hadn't learned anything since then? Did no one even examine Dr Watson when this happened?"

"I believe he said Poppy did," said the Scottish witch, "But I think Hildegard is right—is this really something we can afford to investigate? As fond as I am of Dr Watson and sympathetic to his plight—this is a genie we cannot afford to let out of its lamp."

There were murmurs of agreement around the room. It was a valid point, Sherlock had to admit. As much as he abhorred the hiding of knowledge—any knowledge—how many lives had been lost over the centuries due to untrammelled curiosity? Would the world be better off had the nuclear bomb never been invented? Chemical warfare? Gas chambers? The guillotine? What if trying to cure John opened such a series of catastrophes on the members of the magical world, like a swath of epidemic cutting down entire families and consigning them to live … well, a normal, magic-free life. (Oh, the horror.) Really, would that be so terrible? John had managed, after all.

And … this was John.

Although, of course, John was so self-sacrificing, he probably would opt for the decision best for the greater good.

Sherlock pulled out his phone. "Maybe we should ask John how he feels?"

#

All John could feel was pain.

He vaguely knew he was being supported by the tree—just before all his nerve endings had ignited in this godawful, skin-crisping pain, he had felt himself slam up against the trunk, his head colliding with the bark hard enough to see stars … except, right now, he couldn't see anything. He couldn't see or hear or think. All he could do was scream with the pain flooding his system so that every cell exploded in an inferno of pain worse than anything he had ever felt in his life.

For a small eternity, he hung there, impaled on a lance of flame and pain and agony.

Then, suddenly, it stopped.

He dropped to the ground, panting and trembling as his body shuddered with the relief, every inch of skin feeling impossibly tender. He looked down at his hands, even as his feet scrabbled for purchase, trying to force himself up off the ground. He had to protect the Dursleys. He had to face this threat on his own two feet.

He couldn't give up.

He was almost surprised to see that his hands weren't burnt claws. The way the flaming agony had engulfed them, he had almost expected the flesh to be burned away, but no. Except for some blood from his own fingernails digging into his palms, he was untouched. Or at least, not visibly injured. Just like last time.

He could hear the yelling now, as his friends fought back, sounding outraged now. The witch who had attacked him was battling with Harry now, who looked more like an avenging god than any human had the right to look.

John pulled in a shaky breath, trying to force his legs to stop quivering, trying to clear the smell of burning from his nose.

Burning? What … he looked down then and realized that, while his skin wasn't scorched (no matter what his nerves were insisting must be true), his mobile had somehow exploded or shorted out or whatever modern technology did. Its screen was cracked and there was a wisp of smoke coming from it. He stared at it in wonder, unable to flog his brain into figuring out what had happened. It was hot to the touch, too, he thought, which made sense for a smoking, melted plastic thing, but he couldn't quite bring himself to drop it.

He felt a hand tugging at his arm. "John? Come on, John."

No, he thought. He wasn't going to retreat just because he was the poor, helpless Muggle. He had been a soldier, damn it, and even if he was out of ammunition for fighting back, he wasn't going to retreat from the field. What if someone was hurt? What if they needed him?

Still, he supposed stepping around to the other side of the tree might not be a bad idea. There was no shame in taking cover during a fight, was there? He glanced over at Hermione's concerned face and then back at the Dursleys, staring at him in horror. "M'okay," he said, turning back to the fight. Harry and Ron were back to back, now, and there were only two opponents left standing, clearly on their last legs.

From old habit, his eyes skimmed over the downed bodies, looking for injuries, calculating triage needs and resources in his head. It looked like they were all unconscious or bound, so they weren't a ris… no, wait. Movement! One of the masked figures was shakily lifting his wand, aiming it at a distracted Harry as he focused on his own opponent.

John looked around frantically, but nobody else saw the threat. He opened his mouth to yell, but instead of the warning he'd intended, he shouted "Protego!" out of sheer instinct … and felt the wand in his hand burn.

#

Sherlock looked down at his phone. He supposed John was probably busy at the moment. Ah well, the question of his magical injury had waited twenty years … twenty more minutes wouldn't make much of a difference. No doubt he would text when he could.

He wondered if it would make a difference. Judging by the clothing in the portraits and the paraphernalia around the office, how much had things really evolved in the magical world? Would their research methodology actually allow for a better outcome if they were to explore the topic? He wondered how long it would take him to learn enough about witchcraft, or whatever these people called their magic, to be able to help—because surely that would make a difference?

He was prowling the room again, unable to sit still. Yes, he understood that John was busy out there in the absurdly-named Forbidden Forest, but surely he had the time to send a text? Philosophical conversations about magic versus science had lost their appeal now. All he could think about was John's loss. Because wasn't that what friends did? Concerned themselves for each other's well-being?

Although, would a return to this absurd, magical world be a good thing for John? He certainly seemed happy enough with things as they were. True, he had seemed uncertain since yesterday's crime scene at Little Whinging, but that could be explained by having bumped into his old friends, having the old loss resurface. It didn't mean he would want that to change permanently … did it?

"You're worried."

Sherlock turned around, levelling a glare at the portrait of Dumbledore that the others all seemed to yield to. "John can take care of himself."

"That's not what I meant, young man. You're torn between wanting to help Dr Watson recover his magic and dreading what the result of that would be. You're afraid he would abandon you to return to the wizarding world—even though loyalty has always been one of the hallmarks of Dr Watson's character."

"What difference would it make?" he asked, as if the answer held no value to him. "It's not like he would have to move out."

Would he, he wondered silently.

"It's true that, as a rule, the Muggle and wizarding world are kept separate for a reason. It's hard for them to co-exist—if a wizard absently casts a spell while sitting in a Muggle pub, or walking down the street … well, the Statute of Secrecy exists for a reason. As a rule, Muggle brains refuse to accept the reality of magic. And with more and more Muggle devices to record things, well, keeping an entire world secret is more difficult than ever. Then, of course, sadly, many witches and wizards think … poorly … of Muggles and consider socializing with them to be beneath them. Incorrectly, of course, but still—separation has always been the safest and easiest defence." The image tilted its painted head. "That being said, of course, there are wizards from Muggle families who naturally keep in touch with their loved ones. Wizards living in London, surrounded by Muggles. There are friendships and even mixed marriages—ones that face more difficult challenges than differences of colour or religion—but which can work."

Sherlock shrugged. The whole topic was dull. So dull. Not something he'd be interested at all. He glanced back at his mobile, considering the benefit to sending another text. He glanced back up, finding a wall-full of eyes watching him. "I certainly hope you don't think John and I are in any kind of romantic relationship. We are friends and colleagues, nothing more. I just dread the thought of having to find another flatmate if he were able to return to …this." He waved his hand to encompass the room.

Before Dumbledore could reply, a silvery stag burst through the wall and spoke in Harry's voice. "We're on our way back—heading for the hospital wing. John says to tell you he's fine."

Sherlock stared. The hospital wing? That implied injuries, and … John saying he's 'fine'?

He glared up at Dumbledore's portrait. "How do I get there?"

#