Disclaimer: Even after 10 years, JK Rowling still owns Harry Potter.

A/N: You may not know it, especially my AO3 readers, but today is a big day. Today is the 10th anniversary of the Animagus-Verse, and of my entire fanfiction career. It was 10 years ago today that I posted my first chapter on FFN. Thank you all for your support over the years, and yes, I am still committed to finishing this story. It might not be as long as I originally planned, but I do have a plan for 7th year that I hope will bring it to a satisfying conclusion.

Other notes: My explanation for dementors in this chapter may contradict some of the lore I established earlier in the series. This was a necessary change, as even after all this time, I was still struggling to understand the paradoxical nature of dementors—that they both feed on, and are repelled by positive emotions. This time, I finally found an explanation that clicked into place; to my surprise, the analogy with depression turned out to be the key rather than an extra complication to be dealt with.

Also, if I've made any mistakes with the real-world history of this time period in this chapter or the characterisation of certain person, well, just remember that we're firmly in alternate history at this point.

Chapter 35: Frost

"I'm telling you Savage, I am this close to going up to Buckingham and asking the Queen to dissolve the Parliament today. Go on and hold the election before February's out! Get it out of the way! It'll be worth it to get out of this madhouse."

Prime Minister John Major was just about at his wit's end. With the bitter cold that had settled over England, nerves were frayed, and infrastructure was strained to the breaking point. The "terrorist attacks" (well, they were terrorists, just not the kind he could deal with himself) were continuing unabated, and more and more people were starting to notice that they didn't match the pattern of the rest of the Troubles—or any strategic pattern at all. Meanwhile, the latest NHS report had documented such a large increase in depression and associated illnesses that it was discussed on the evening news. (Luckily, doctors were blaming the weather.) And, for what little it mattered anymore, his poll numbers had plummeted to their worst level in his entire term in office, and that was saying something.

"Perhaps that would be best for you personally, Prime Minister," his witch bodyguard said. "I can see how the stress is getting to you. Unfortunately, I'm afraid it won't do much for the national crisis…Sir, the report from Switzerland—" she began.

"Officer Savage," he stopped her. At some point, he'd become annoyed enough that he refused to use that ridiculous "Auror" title of theirs anymore. "Unless it affects us, I. Do. Not. Care. You told me that there was nothing I could do practically and to take care of my own people. I'm expecting you to take care of yours."

Savage took a deep breath as she bit back whatever retort she was going to make. "You should know that there was a possible Ebola contamination, sir," she said. "The victims are in quarantine now, but we know that isn't one hundred percent secure."

Major sighed. The good thing about the EU's containment efforts was that cases of the disease in Western Europe had remained rare. But that also meant any cases in Western Europe were a serious matter that needed to be brought to his attention, and an alarming number of them were being caused by wizards. "Fine," he said, "if there's any—"

But he didn't get to finish because they both stopped as a harried-looking aide ran into his office holding a sheaf of papers. Savage, following the usual procedures, stepped in the lad's path and ran her wand over his body to check for curses and whatever other magical threats she was worried about—under the guise of a handheld metal detector—before letting him approach.

"Mr. Prime Minister, we have a problem with the Provisional IRA," the aide said.

"When don't we?" Major grunted as he took the papers.

"They just firebombed one of their own commanders, sir."

Major froze and looked more closely at the report. He recognised the victim's name at once. It was the same commander who had taken credit for several of the "unusual" bombings in recent weeks—that was, the magical attacks. "What in the world…?" he muttered as he skimmed the report. "Rest of the group takes credit—blah blah blah, condemn his actions—blah blah blah, attacked without warning civilians—blah blah blah, not authorised—right, so basically, they're trying to save face after the last few attacks." He sighed and shooed the aide away with a brief, "I'll take care of this."

When they were safely alone again, he handed the report to Savage. "What do you think?" He had a good guess on the non-magical side, but the wizards' operations were harder to follow.

For Savage's part, she needed only a few moments to pick out the important facts. "Imperius," she concluded. "They wanted to blame attacks on muggles on the Provisional IRA, and when they wouldn't play ball, the current 'Ministry' Imperiused one of their leaders to take credit."

"Not realising the rest of the PIRA would get antsy about one of their commanders going rogue," Major said. "Well, as unfortunate as it is, we can deal with the fallout from this for the moment."

"As long as the Death Eaters don't go to extremes looking for new ways to cover up their actions," Savage pointed out.

Major's frown deepened. "Damn, you're right. I only was thinking of the PIRA having the same problem again. Hm, contact…whoever it is you're supposed to contact for this sort of thing. Tell them to start blaming attacks on poorly-maintained space heaters and people trying to light a fire in their kitchens. That should keep a lid on things until spring and give us time to respond."

"Alright, Prime Minister," she said with a hint of reluctance. He knew it wasn't exactly safe to pass messages through to the Death Eater-run Ministry, but there wasn't much choice under the circumstances.

"But my main problem is this," he continued. He picked up the copy of the Daily Mail and slapped it down on his desk for emphasis. The front page showed a photo of a man testing the ice at Battersea Park. "They say it'll be all the way down to the Tower Bridge if this weather goes on another week—and you say it will."

"Unfortunately, yes," she said. "With the dementors running loose, we can expect the weather to stay colder—"

"This is getting out of hand!" he cut her off. "Maybe it's just a curiosity to you, but London's not equipped to have the Thames freeze over anymore. And it's not just the Thames. Ice on the roads, snow drifts. The city's grinding to a standstill. The weathermen have stopped saying 'unseasonal' and started saying 'unnatural,' if that gets your attention. And, people are talking in the streets about holding a bloody Frost Fair…Do you even know what that means?"

"Of course I do," Savage snapped, sounding offended. "The Great Frost is still talked about in magical history." By that, she had to mean the Frost of 1683 and '84, which now that he thought about it was before the wizards went underground.

There was silence for a minute, neither of them quite sure how to answer that. Major still felt like they were talking past each other. And then, Savage said something that even after everything that had happened still threw him for a loop.

"Maybe you should…let them?"

"What?"

"Hold a Frost Fair."

"Are you mad, Officer Savage? It's out of the question."

"Why?"

"Why? Because it's not 1814 anymore. Things like that don't just happen in this day and age. Safety, security, planning. The number of people who drowned in the last Frost Fair alone when the ice broke up would be a—well, a tragedy, of course, and also a PR nightmare."

"Which you won't have to deal with for much longer anyway," she pointed out. Major gave her a look, but she had already moved on: "But surely, you have enough manpower to monitor the ice. Even, what do you call them? Electronic sensors? I know the muggle government's resources have grown a lot since—1814 was the last Frost Fair?"

"Yes. I looked it up; they talked about having one in 1881, but they didn't for reasons that even I couldn't find, but I'm pretty sure were good ones. And it's not just the ice. There's the kind of people who will be running around out there. And don't get me wrong; there will be a lot of average men and women on the street, too, but legitimate business owners aren't equipped to haul their wares out on the ice like they were back then—not on a whim, anyway. You're going to get the con men, the troublemakers, heck, even the homeless people along the river if any of them can stand the cold." He'd been working with the Mayor of London on that, of course, and they were doing the best they could with that, but it was never perfect. "And then there's the police not being prepared—God, it's going to be bad enough just with them trying to turn away the thrill-seekers."

"Only if you tell them to," Savage said.

Major leaned over his desk, staring her dead in the face: "Give me one good reason why I should."

"Because it might actually lift the freeze."

There was silence once more. Out of all the things she could have said, that was the last thing he expected. It was…nope, it made no sense at all. He wasn't a wizard.

"Come again?" he said dumbly.

Savage took a deep breath. "That's what I was going to say at the start. Look, the cold weather is being caused by dementors roaming the country. Now, dementors are hard to understand because they're conscious spirits—entities—what have you. The point is they can think; they're not just forces of nature. But I've spent enough shifts in Azkaban to understand how they operate, and the fact that Londoners are even capable of talking about holding a Frost Fair seriously suggests that if you actually hold one, if could drive them away.

"And how is that?" he humoured her wearily. "Your lot told me ages ago that dementors feed on positive emotions, and that's why everything is so dreary right now. Won't a big celebration attract them?"

"No, for a couple reasons. First, dementors don't go for muggles normally. And if there's one thing You-Know-Who's Ministry is doing right, it's maintaining the Statute of Secrecy. They're giving dementors a lot of latitude, but not enough to attack where muggles will see. But there's another reason, and it's because this Frost Fair is being organised organically, not imposed from here as some sort of morale booster."

"What like bread and circuses?" Major said disdainfully. "Like the people wouldn't see through that?"

"I'm not saying you'd do that, but I've seen Ministers of Magic who definitely would."

"Hmpf. Fine, but you haven't answered my question. What does the Fair being organised organically matter?"

Savage started speaking faster. "Okay, the paradox of the dementor—or really the paradox of the Patronus Charm—is that dementors feed on positive emotions, but the Patronus Charm radiates positive emotions, and yet it still repels them. The solution to the paradox is that you're not seeing the whole story. Dementors don't just spread misery; they suck the positive emotions out of things that are normally happy. They grow where there's decay and despair because that actually means they have a steady food supply, eating all the positivity we don't see."

"They're eating the…missing part?" he mused, mostly to himself. It did make a twisted sort of sense, but "sucking all the happiness out of a room" was supposed to be a metaphor. It wasn't supposed to mean that the happiness still existed somewhere.

Savage kept talking: "The Patronus Charm works because it's a spiritual shield. It radiates positive emotions because it blocks the dementors from feeding, letting the emotions spill out. It might even drain their strength—or maybe burn it out, you might say. As far as I know, no one's been able to keep a dementor contained by Patronus up close long enough to say for sure—but that's beside the point."

"Yes, it is, because I don't think the Frost Fair has a 'spiritual shield,' whatever that's supposed to mean."

"That's just the thing, Prime Minister. I think it might do."

He glared at her. "In case you haven't noticed, Officer Savage, we can't cast a spiritual shield over London."

Now, astonishingly, she smiled: "But you already are. We say muggles are people without magic, but the greatest magic is spiritual in nature. The deep stuff. In fact, a muggle-born once described it to me as 'Deep Magic.' A mother's love for her child—that sort of thing—the sort of thing that's not about waving wands or brewing potions. Dementors—and the Patronus itself—get into that territory."

"And…?" he pushed her impatiently.

"Wizards who work with muggles say that dementors mimic the symptoms of depression. Isn't one of those symptoms loss of interest in things you normally enjoy?"

"Yes, it is."

"Well, I don't claim to be an expert in depression, but I told you I know enough about dementors from Azkaban, and that's exactly what they do. But if you can generate happiness organically that's strong enough to overpower the dementors' gloom, that will weaken their hold over a wide area—a wide area like London. That's the Deep Magic. And if people are seriously talking about holding a Frost Fair unprompted, that means, for whatever reason, the idea of it is stronger than the dementors' gloom."

"That's not really how depression works, to my understanding," he protested. "We have medications for it for a reason."

"And depression isn't fought by magical spirit guardians, either. My point is that the Fair might help with the dementors for the same reason the Patronus does. If the positive emotions are too strong to be broken by the dementors, they can't feed properly."

The Prime Minister crossed his arms and thought for a long while. That chain of logic…did hold together when she laid it all out like that. And she had no reason to lie to him and more reason than most to know what she was talking about. And if it worked…well, it would be very good for the non-magical United Kingdom, and he didn't particularly care was the wizards thought.

"There's still the risk that the dementors could come after the fair," he said.

"There's also a risk they could come after a football match next summer. In fact, it might be a greater risk. Dementors would treat a one-off sporting event concentrated in a stadium very differently from a week-long fair sprawled up and down the river. Looking back, we might've got lucky last year in that regard."

Major sank down in his chair and covered his face with his hands. "I'm calling the election," he groaned. "You, connect me to Fudge. If he agrees with your scheme, I'll lean on the Mayor to officially allow the Frost Fair to go forward."

"Dumbledore would be better, but I'll see what I can do, sir."

John Major had only met Albus Dumbledore briefly in the past, but he apparently was both considered the wise old sage among the wizards, and was also admired for his magical power in a way that was reserved for comic book heroes in the non-magical world. Whatever his office, when Officer Savage had explained her plan to him through the magic mirror, he had immediately agreed and even praised her for her clever thinking. And that was that.

The press had had a field day that week. The first Frost Fair in nearly two hundred years, the elections called so early in the year, and Major had stunned his own party when he said that he would not only step down as the party leader, but wouldn't stand in the election at all, citing "health concerns."

And then he had to explain everything again to Tony in private, wondering all the while if his counterpart would decide it was too much, too.

But one thing had worked out, at least. Looking out at the now-underway Frost Fair from Westminster, Major had to admit he'd been wrong.

The Prime Minister had been unsure of even how people could set up a Frost Fair in modern times. People didn't have wooden booths just sitting around to set up somewhere on a whim. Well, street pedlars did, but brick-and-mortar stores didn't hawk their wares on the streets anymore—or certainly not like they did in the nineteenth century. There was certainly no time for practical organization and planning (part of the reason why he hadn't wanted to make it official). In several past Frost Fairs, people had barely had time to set up before the ice broke up, and modern fairs and carnivals were much more involved. Also, food trucks and trailers couldn't go on the ice safely. He'd insisted on that point to the police, despite the stunt of bringing an elephant onto the ice in 1814.

But Mr. Major was surprised, even pleasantly so, by the results. While he'd been complaining and worrying about it, the people of London had been thinking about the possibility that a Frost Fair would happen, talking about it with each other—idly up until the announcement, but in earnest afterwards. They had been watching the progression of the ice, even rooting for the historic cold to continue for the simple reason that there was nothing else to do in such a dismal winter.

And as they thought, they began to think of options. Food trucks couldn't go onto the ice, but grills could. People couldn't set up proper stalls on such short notice, but the could haul out card tables and cafeteria tables onto the ice, draped with curtains and loaded up with simple and sometimes even amateur crafts—the sorts of things people set up for bake sales, craft shows, and comic book conventions. And they couldn't (for the most part) set up modern arcade or carnival games, but people got surprisingly creative with ad hoc adaptations of lawn games like horseshoes, bowls, croquet (somehow), and a favourite of historical Frost Fairs: nine-pin bowling—along with the usual winter activities like ice skating and ice sculpture.

The police were keeping order admirably—along with monitoring the ice and ensuring no one went out on the much more dangerous thin ice below the Tower Bridge. And they did have their work cut out for them. The 1814 Frost Fair had stretched for less than a mile from London Bridge up to Blackfriars Bridge. The 1684 Frost Fair had extended two miles, up to Whitehall. But London's population had grown five-fold since that time. The Great Frost Fair of 1997 sprawled across four miles of the Thames, down to the Tower Bridge and all the way upriver to Battersea. And as far as he could tell, people were enjoying themselves. And that, ironically, made the Great Frost Fair self-limiting (much to his relief), as it only took a few days of activity on the river before the cold began to lift.

Augustus Rookwood, the (alleged) Minister for Magic, was not having a much better time of it than his muggle counterpart had last week, not that he knew that. This blasted muggle fair, sprung on them with no warning, was throwing all of Wizarding Britain out of balance. Their movement in London was impeded. The dementors were getting riled up. The Dark Lord had noticed. And they couldn't even do anything about it because it was so public. The only consolation was that he strongly suspected it would be over in a few more days.

Romulus Mulciber, as the (alleged) Head of the Department of Magical Law Enforcement, gave Rookwood his latest report on the situation.

"Quite a few curious wizards going out on the ice despite our warnings," he said, "but with so many muggles around, we've been forcing the dementors to hold back. I've been worried what would have if this mess went on a lot longer, but I think we might get lucky. The freeze is lifting over London, and the dementors are drifting back north on their own, so we just might see both our problems solved."

"Well, that's one good thing," Rookwood said.

"Yes, it's good…It's just that it's a notable change in their behavior. There are some mutterings in the ranks that the Fair had something to do with it."

Rookwood was silent and looked darkly thoughtful, a look Mulciber knew all too well. "Damn. I hoped there was nothing to that," he said. "What is it?"

"The Unspeakable have a…more complex view of magic than most wizards," he said. "At least in private. Magic is everywhere. You can never fully be rid of it, even if you try. And the magic of emotions is especially pernicious. We can leave aside the question of muggle-borns and whether or not they steal their magic. Even if it's true, the descendants of squibs have spread throughout the muggle population for centuries, and squibs still have enough magic to see through wards. We say they don't, and for good reason, but they aren't completely deprived. A large enough concentration of muggles enjoying themselves in spite of the dementors' gloom? That could be equal to a few good Patronus Charms—enough to push them away."

Mulciber's reaction was colourful and less than becoming of a normal Ministry official. "So, what do we do?" he finally asked.

"Nothing. The Fair will end soon, and lifting the freeze on London will get muggle suspicion off our backs. But one thing is certain: no one speaks of this to the Dark Lord."

Mulciber shivered, and not from the cold. "Got it."

It was a shock at first in France, seeing the photos in the papers of people dancing on the frozen Thames in the shadow of the Tower Bridge. It was a bigger shock to learn from the magical papers that the first Frost Fair in nearly two centuries had been (it was believed) caused by the bloody Death Eaters, setting the dementors loose. In fact, it was kind of funny in a twisted way.

Harry and Hermione met the news of the Frost Fair with melancholy, especially on Hermione's part. It wasn't about the celebration itself. There were surely more exciting winter carnivals in colder climates where they were properly organised, and Luna was even able to suggest some specific ones from when she'd gone on holiday with her father in Scandinavia. Rather, it was missing out on being a part of history. A Frost Fair was at best a once-in-a-lifetime event and more commonly regarded as a relic of the past that would never happen again. The world was warmer, they said, and the Thames embankment made it less prone to freezing on top of that. But of course, the pair couldn't go thrice over—once because they were in quarantine, twice because they couldn't show their faces in Britain, and three times because witches and wizards were being asked to steer clear of the muggle gathering anyway.

As usual during their quarantine, Healer Muamba brought in their newspaper.

"How are you feeling today, Mr. Potter? Ms. Granger?" she asked.

"Meow," said Harry. Both Muamba and the otter sitting across from him rolled their eyes at him.

Oh, right. There was a slight fourth reason they couldn't go up to England in their present state.

"I have been told that both of you are Animagi," Healer Muamba had said on the second day of their confinement. "A cat and an otter?"

"Yes. Why?" Harry asked.

"Animagi are more common in Africa, and some of those who learnt the art spent time in their animal forms to try to protect themselves from the disease."

"Did it work?"

"Somewhat. It did not prevent them from contracting the disease that I could see, but it did lessen the symptoms considerably. I also talked to some muggle doctors, and they say the virus has been found in dogs without symptoms. It appears it does not hurt animals as badly."

"Should we just spend the quarantine in our Animagus forms, then?" Harry asked.

"That would probably work, Mr. Potter, but I am worried it could prolong your quarantine period. We still don't know how animals fight off the disease. And as has been made abundantly clear to us, for you, a prolonged quarantine is a risk in itself. My best advice would be to spend twelve hours per day in your Animagus forms. If you begin to show symptoms, we can change it depending on your progression."

So far, it had worked, although whether that was because their Animagus forms fought off the virus or because they were never infected to begin with, the didn't know. They had taken muggle tests for Ebola, which had come back negative, but Healer Muamba had said the tests could be thrown off by their magical metabolism.

They were cautiously leaning towards "not infected." Harry recalled the Inferius that had bit him had been eyeless and skeletal, part of why he had been cut up so badly—the sharp bones—so it probably was not infected. The one that had attacked Hermione had been fresher, although her injury was much less bloody. Their parents had, understandably, read up as much as they could on the subject and had found that Ebola was not that easily transmitted through bites. It wasn't a zombie plague, after all.

Although all evidence pointed to the fact that Ebola was being spread in the refugee camps in the Balkans by Inferi (which was placing increasing strain on the local governments). And if the bodies had all been stuffed in a box together to transport them or something of the like, the infection could have spread among them then. But even so, Harry still believed they would be fine.

Of course, that really meant that they "only" had Voldemort to worry about.

Scotland was not as fortunate as London in the weather department. Being so far north, Hogwarts (which regularly got copious amounts of snow and ice to begin with) was in a deep freeze—so cold that no one wanted to go outside the castle. Even the Quidditch fanatics couldn't find enough people willing to go out in the cold for a match, and several who tried found themselves in the Hospital Wing afterwards. Far from London, the gloom of the dementors did not lift so readily without the Frost Fair to drive it away, and at the rate things were going, the grounds might stay below freezing until Easter.

This had real consequences besides inconvenience to the students. The Black Lake, which normally stayed at least partly ice-free even in the dead of winter, had frozen over so thickly that it posed a threat to the Merpeople. In response, they had done…something to bash through the ice, probably involving the Giant Squid, and had entered into some tense negations with the so-called Headmaster to ensure their safety long-term. The Death Eaters didn't want to deal, but letting them all die would have been a bridge too far for the ICW and for the centaurs in the Forbidden Forest. It would be more trouble than it was worth, or so the best-connected students said. And Romilda liked to think she was very well-connected by now.

In the present environment, any overt actions related to the war were in a lull. With the cold, the students were focusing all the more on their studies inside the school—both licit and illicit in the teachers' eyes—although since the detentions for slights against the Death Eaters were increasing in severity, they had to be careful even of that.

Publicly, the older students were working on learning the Patronus Charm, which the Death Eaters didn't exactly like, but they couldn't very well oppose because even they needed people who could use the Patronus Charm to work with dementors safely. This wasn't entirely altruistic, though. There was a rumour—no one really knew where from—that the Patronus Charm could be used to securely send messages that couldn't be faked. But of the few who had learnt to cast them and were secretly trying, no one had figured out how to do it yet. Maybe it would pan out eventually.

But this wasn't the only war effort going on in Hogwarts. There were still some students who were working quietly against the Death Eaters directly. And not the only, but possibly the most fanatical of them was Romilda Vane.

Although her fanaticism still didn't leave her with much she could do with it yet. She wasn't ready—but she would be. Harry Potter had said she needed to learn some basic Occlumency before she started plotting things, so by Merlin, she was going to learn Occlumency.

The trouble was, the only books in the library that talked about Occlumency were in the Restricted Section, which made them difficult to access. She didn't know if that was a Death Eater policy, or if it had been like that before, but with the current teaching staff, that meant you pretty much had to be an elite pureblood or junior Death Eater to even look at them without raising suspicion. That meant she and her compatriots didn't have the books, nor any copies or transcripts of them (that was a protection that had been on the Restricted Section before), but only notes on their content taken by hand, no magic involved, hastily scribbled in their limited windows of opportunity to read them.

She hoped that was enough to learn what she needed. She was trying, anyway. The bare minimum basics were easy enough—avoid eye contact with suspected Legilimens and focus on other topics in your thoughts. It wasn't "don't think about it." The book had made very clear that never (or almost never) worked. Instead, you had to fill your thoughts with something else, unrelated, so you could actually push the secrets out of your mind.

When they thought about it, the need for Occlumency wasn't all-encompassing. She and her friends actually weren't too worried about the Carrows. Those two seemed like they were as dumb as a box of rocks. But Barty Crouch Jr., the so-called Headmaster, everyone said he was smart—as in Hermione Granger-smart. Romilda would be surprised if he wasn't a Legilimens, and she did her best to steer clear of him. She had to admit that if they did try to kill all the Death Eater teachers, he would be the hardest nut to crack.

And then there was Snape. Him no one was entirely sure about. They were pretty sure he was a Legilimens. But there were also rumours of him being a double agent that she really didn't know what to make of. Romilda hoped that if they made a move, he would stay out of the way, but they couldn't count on that.

Ultimately, Occlumency was only the first step. Romilda thought she and Cormac and their friends could manage the Occlumency well enough, but if Harry was going to trust her with anything really important to the war—which he implied he would—she needed to be extra sure. They needed to test it—come up with a useful plot on their own and see if they could carry it out without getting caught. And, as Cormac had convinced her to really think about it, they needed to be able to make a quick getaway if it went wrong—or more likely, if the Death Eaters started rooting through the student body after the fact. And that meant there was only one day to do it. She resisted the urge to draw a circle around the day before Easter holidays on her calendar.