Disclaimer: JK Rowling owns Harry Potter regardless of any reasonable estimate of your position in spacetime.

Part of this chapter is quoted from Harry Potter and the Philosopher's Stone.

A/N: Thanks to Hermione destroyer of worlds for suggesting that Hermione could find the Philosopher's Stone in a muggle encyclopedia.

Chapter 16

The ride back to London on the Hogwarts Express was pleasantly uneventful. Hermione found a compartment with her older friends from the Quidditch teams, which proved to be wise, since it cut short Draco Malfoy's efforts to accost her.

The only problem was that as the afternoon wore one, Hermione's estimation of distances and times seemed to be slipping a little. She had confirmed through her parents' letters that the train was to arrive at King's Cross at precisely seven o'clock. However, from the look at the countryside, she was starting to think that they were closer to London than they should be, and when they crossed into Greater London with an hour left to go, she was sure they were going to be quite early. She mentioned this to her friends, who just shrugged and told her that the Express was always on time. Even when they were nearly there, and she insisted that they were going to be half an hour early, Alicia reassured her that there was no problem because it was magic.

Hermione thought that seemed like a whopper, even for Hogwarts, and it certainly didn't stop the train from pulling into Platform Nine and Three Quarters at six twenty-five in the evening, by her watch. Still, she sighed, wished her friends a happy Christmas, and rolled her trunk off of the train. She walked up the platform, looking for a bench to sit down and wait for her parents to arrive. This proved to be a bit difficult, since the platform seemed oddly crowded for getting in so early. She was about to give up and just stand by the barrier into the muggle world when…

"Hermione?"

She turned and saw her parents walking towards her.

"Mummy! Daddy!" It was all she could do to keep hold of her trunk as she ran to them. She leapt into her father's arms, and he spun her around once before handing her off to her mother. After the Halloween incident, they were extremely eager to see each other, and her mum squeezed her till she couldn't breathe and cried softly into her shoulder.

"Oh, it's so good to see you, baby," she said.

"You too, Mummy."

"We've really missed you," Dad said. "And what with all the stuff that's been going on…"

"I missed you, too," Hermione said. "It's hard getting used to being away from home."

"Well, at least you've made plenty of friends," Mum said. "I don't think you've ever had so many friends before."

"Mummy…"

"Come on," Dad said, kissing her on the top of her head. "You have all your things?"

"Uh huh. But what are you doing here so early?"

"Early? What do you mean? We're right on time."

"No, the train came in half an hour early."

"It did?"

"You mean you've been waiting for us for half an hour?" Mum said worriedly.

"No, we just got here. That's the thing."

"Hermione, I don't understand what you're talking about," Dad said. "The letter said seven o'clock, and the train pulled in at seven o'clock."

"No, it didn't. We pulled in at six twenty-five—" She checked her watch. "—four minutes ago."

"But it's seven—"

All three of them stopped short as Hermione and her father held out their watches side by side. Her own watch said six twenty-nine, but her father's said seven oh-four.

"What? But how…?" she said.

"Hermione, did your watch stop?" Mum said.

"No. Look, it's still ticking. And it's been matching the bells all term and everything. It was fine at the castle this morning…huh, I wonder…"

"What?" Mum and Dad said.

"Well, I told you that the castle changes slightly over time, didn't I? If space isn't constant in Hogwarts, then maybe time isn't constant, either…" Her face fell as a horrifying thought crossed her mind. "Dad, please tell me it's still the twenty-first of December, 1991."

"Of course it is," he reassured her. "I think one of us would have noticed that. Come on, let's get you home."

Mum and Dad walked Hermione out to the car and loaded her things in the boot. They stopped at a drive-thru on the way out of London for some Indian takeout. (Hogwarts really was behind the times, Hermione thought. She wondered if she could teach the elves to make chicken tikka masala.)

"You're awfully quiet, Hermione," Mum said as they drove back to Crawley.

"I was just thinking about the time thing. If the time drifts back and forth at Hogwarts, then sunrise and sunset must drift, too, according to the clock, right? I mean, thirty-five minutes early is a minimum of three hundred miles west, even in the highlands. Even if the castle could change its actual position on the Earth, that far would take it clear out of Britain."

Emma Granger knew better than to question her daughter's calculations. "I suppose so. Have they?"

"I don't know. I haven't been paying that much attention, but I think they might have. And I'm starting to wonder if that's deliberate."

"Oh?" Why's that?"

"Well, in Hogwarts, A History, it says that the location of Hogwarts is secret. All magical schools are. It makes sense, really. If almost every magical child in Britain lives there nine months of the year, it's the kind of protection you'd want to have. Anyway, Hogwarts is already unplottable—that means magic will prevent you from marking it down on a map—but if you knew the latitude and longitude, you could probably still locate it, and you could get those by watching the sun and stars. But if sunrise changes unpredictably from day to day, then you wouldn't be able to use it to determine your exact longitude." Come to think of it, she thought they had never actually used altitude and azimuth in Astronomy class—positions on the sky relative to one's location and the time. They'd learnt the theory, but in the practical portion, they always aligned on the Pole Star and used right ascension and declination from there—coordinates that didn't need to be specified relative to anything on the Earth.

"I guess that makes sense," Dad said. "That seems like a lot of magic just to protect a location, though."

"So's making it unplottable," Hermione replied. "It would have to affect map-making throughout the entire country, if not the world. That would take an awful lot of power. I don't really know much about area effect spells yet. I think it has something to do with runes and ley lines—I think they can draw power from the Earth itself somehow."

Many of their conversations went like this. Hermione was very grateful that her parents took an interest in what she was learning, even though it was so different from muggle subjects, and that they were smart enough to not only get a good grasp of magical theory, but also to contribute their own perspective on things. Granted, they were just as mystified as she was by a lot of the idiosyncrasies of magic, like the literal "no free lunch" rules of transfiguration or the metaphorical aspects of potions, but they did make some good points for thinking about potions by analogy with chemical reaction networks and drug interaction tables. Of course, on the more mathematical subjects like Charms and Arithmancy, they just let her do her own thing.

It was good to be home, Hermione thought. It was nice to be able to have longer conversations with her parents than she could put in her letters about her friends and classes and all the crazy things that went on at Hogwarts. Her parents were as uncomfortable as she was with the house elf situation, for example, but they had to agree that there really wasn't much that could be done about it. All in all, it was a bit annoying to have to stay away from magic for two weeks, but Hermione still slept well that night.

"Happy Christmas, Hermione!"

"Happy Christmas, everybody!"

Grandma and Grandpa had come by for Christmas, as usual. The one problem this year was that they weren't supposed to know about magic, and even if they did, Hermione couldn't demonstrate it, so she and her parents reluctantly decided not to tell them, which led to more than a few awkward questions about school. They had decided to describe Hogwarts as a school with a rigorous science program: Charms was Physics, Potions was Chemistry, Herbology was Biology, and so on, but they couldn't get into too many specifics. They also couldn't very well tell them about the troll incident, for example, since there was no way to convincingly dress that up with a muggle cover story.

But they were all focused on opening presents this morning, so it wasn't a problem. Hermione did hope her friends had got her owl order gifts: a box of Chocolate Frogs for Harry and Bertie Bott's Every Flavour Beans for Ron. Hermione, of course, received more than her share of books.

But the normal holiday routine was interrupted by her mother's startled yell during breakfast. An owl had arrived at the window. Mum quickly took the parcel from it before Grandma and Grandpa could see what was going on, and passed it off as being caught by splattering bacon. Thinking fast, she finished breakfast and then brought in the parcel.

"Oh, Hermione, I almost forgot," she said. "Professor Vector sent you a gift in the post."

"She did?" Hermione said in surprise. "That was nice. I really wasn't expecting anything…" She took the parcel and read the note:

To Hermione, in the hopes that even you will be able to find a use for it.

She unwrapped her present and gasped. It was a slide rule, but not just any slide rule. It was an incredibly complex circular slide rule made of lacquered wood with two dozen scales on it between the two sides, all set in rings that could be rotated freely and even flipped over, allowing the computation of all kinds of functions that normal slide rules couldn't handle. She could easily tell that it was held together by magic, although she could pass it off as mundane.

"It's beautiful…" she said. Things like this were probably easier to make in the magical world, but something this nice couldn't have been cheap, or maybe Professor Vector made it herself. She wasn't sure if it could actually improve her computation speed, but it would at least be fun to play with.

"Wow, this professor must really like you to send you something like this," Grandpa said.

"Mm hmm…" Honestly, it was a lot more than she was comfortable accepting. Professor Vector wouldn't be the first maths teacher to send her a Christmas gift, but it was a little less unexpected for an algebra teacher to send a little nine-year-old girl an inexpensive trinket than for a teacher to give such a fancy gift to someone who was only two years younger than her other students. "I'll have to try to give her something back," she mused. A calculator would be the most obvious choice, given the circumstances, but it wouldn't work in Hogwarts. She'd have to think about it.

It took until the twenty-eighth of December for Hermione to notice the long row of books on the shelves of the Grangers' library and open up the volume that said "Light—Metabolism".

It was half an hour later when her parents found her sitting on the floor, cross-referencing "Light—Metabolism", "San Francisco—Southern", and "United—Zoroastrianism", that they gave in and asked her what she was doing.

"Well, do you remember that three-headed dog I told you about?" Hermione said.

"I think you mentioned that somewhere between the troll and the Quidditch match," Dad said dryly.

"Well, we think it's guarding something…" And she explained about Harry's trip to Gringotts with Hagrid, and the little package he saw, and their conversations with the Groundskeeper about it. "We've been looking up magical artifacts in the library to see if we can figure out what it is," she finished. "You know, just for fun."

"And are the teachers okay with that?" Mum asked. "It sounds like this is something really important and secret."

"I'm a little concerned with the fact that they're keeping whatever this is in a school," Dad said.

"I'm sure it's perfectly safe," Hermione countered. "And Professor Vector said it's fine if we just look in the library."

"Well, that's nice that you and your friends have something you can spend time on together," Mum said, "but do you really think you'll find anything in the Encyclopaedia Britannica?"

"It's possible. From what I can tell, a lot of muggle notions of magic are distorted, but based on real magic. There's all kinds of mythical creatures in Fantastic Beasts and Where to Find Them, like dragons, and griffins, and sphinxes. Maybe mythical artifacts work the same way."

"But wouldn't the books at school have that?"

"Yes, but they're not very well organised. Most of them haven't even caught on to the notion of indexes. I think muggles think in kind of different ways, so the muggle perspective might be useful."

Hermione kept looking for a while after that. She learnt that muggles had many well-developed traditions of divination, more so than most other branches of real magic. Beyond that, traditional magic dealt a lot in amulets and talismans designed to cure illnesses, ward off danger, and the like. There was quite a lot more of that in myths than in real magic, but a particularly important mythical talisman could possibly be the answer.

Magic rings were another rare artifact that appeared more in fairy tales. Rings of invisibility, like in The Lord of the Rings, were fairly common, but Hermione had seen references to invisibility cloaks in the Hogwarts Library, so that probably wasn't it. However, the Ring of Solomon was supposed to allow the wearer to control demons and speak to animals. And a ring of invulnerability existed in several Norse and Arthurian legends, which could well be valuable enough to be the mysterious artifact. Also from Norse mythology, there was the great sailing ship of the god Freyr, Skithblathnir, which could supposedly be folded up like cloth and stuffed in one's pocket. That would be amusing, she thought, but impractical.

But when she dug into the "Accounting—Architecture" volume, Hermione started to wonder. This just seemed too perfect.

"Hmm, this is interesting," she said. "The Philosopher's Stone. Transmutes base metals into gold and produces the Elixir of Life. That could fit…"

"You think the dog's guarding a Philosopher's Stone?" said Dad.

"Well, it meets the requirements. It's the right size, and it's powerful enough to be worth all the trouble they're going to. But I'm not sure. It seems like it's too powerful to actually exist, even in the magical world. Hogwarts does offer an Alchemy class to the upper years, though. I can look up how real alchemy works when I go back, just to be sure. Hmm…if it is…" She frowned in thought.

"Is something wrong?" Mum asked, seeing her face.

Hermione was hesitant, but she answered, "Er, whatever the thing is, Harry and Ron think Professor Snape tried to steal it—and Professor Snape was acting kind of suspicious, but he seems to have some kind of feud going on with Harry, so I'm not sure that's entirely fair. Anyway, if it is a Philosopher's Stone, that would be a good reason for Professor Snape—or anyone, for that matter—to try to steal it."

"Well, I would hope that a teacher would be responsible enough not to do something like that."

"Yeah, me too."

"You'll stay out of trouble if something does come up, won't you?"

"Yes, Mum."

The rest of Hermione's break passed uneventfully, which was a refreshing change. She kept up with her reading and studying, of course, and she convinced her parents to get a hold of Mr. Andrews to give her a Calculus I final exam before she went back. ("It'll be good practice for sitting the A-level next summer," she said.) Naturally, she passed with flying colours.

Harry had sent her a thank you note for the chocolate frogs. Ron had also sent her a note a couple days later, though she suspected that was a result of Percy bugging him to do it. Meanwhile, even though her Mum had advised her that Professor Vector probably wasn't expecting her to spend any money on a gift, Hermione managed to track down an old, mechanical "Magic Brain Calculator" for a good price. The little device was neither magic nor particularly brainy, but it was a brilliantly simple mechanism that would probably speed up an average person at arithmetic quite a bit, and she hoped it would be something that Professor Vector hadn't seen before.

By the end of the break, Hermione was eager to get back to learning magic and, finally, really well-rested—which she hoped would stay that way.

"I hope your friends had a good Christmas even though they were stuck at school," Mum said as she was packing up the night before the train ride back to Hogwarts.

"Ron had his brothers," Hermione replied. "I'm sure Harry liked it. It sounds like almost anything would be an improvement for him."

"What do you mean?" Mum said with concern.

"Well, I told you I thought he's had a rough time at home…I'm a little worried about him, actually. You know the story of You-Know-Who and Harry's parents?"

"You-Know-Who? From the books?"

"Yes. His name was Voldemort—I think—but he's kind of like the Bogeyman, so everyone calls him You-Know-Who. Anyway, Harry says he was sent to live with his aunt and uncle after his parents died. And he said they don't like magic, which is one thing, but he also said his aunt called him and his parents 'freaks', and they make him do all the chores, and they accused him of cheating when he got better grades than his cousin."

Mum and Dad both stopped what they were doing.

"That sounds pretty awful," Mum said. "Is he okay?"

"He seems okay most of the time. He's actually happy to be away from his family, but he seems pretty normal otherwise, except…"

"Except what?"

"I didn't think much of it at first, but he's really small and skinny, too," she said nervously. "I thought it was just because he's one of the youngest boys in our class, and he eats fine at Hogwarts, but…"

"But that's not a good sign," Dad finished for her.

"I know. I don't know what to do, though. I mentioned that he might look if he can find another place to stay for the summer, but any time I bring any of it up, he just brushes it off and says not to worry about it. I don't want to push him too much or anything, though. I don't think he likes to talk about it."

"Has he told any of the teachers?" Dad asked.

"I don't know. I feel like he wouldn't really want to."

Mum sat down beside her and put an arm around her. "Hermione, this isn't something you should let go," she said. "I'm not saying you should pressure Harry too much, but if you suspect something's wrong, you really owe it to him to at least tell a teacher. He may not like it, but he'll be better off in the end."

"Hmm…I guess you're right…" she admitted. Professor Vector was always easy to talk to, despite her reputation, so she could at least tell her. She tried not to think too much about her real worry: that Harry would be angry with her about it.

Hermione's first few days back at Hogwarts were a whirlwind of activity: getting started with classes again, hearing all about her friends' holidays, and catching up on the goings on in Hogwarts from Harry, Ron, and the Twins. (To her dismay, they had barely touched the library aside from Harry's failed attempt to get into the Restricted Section.) She also wasn't too happy with Harry's and Ron's nighttime escapades—she had a feeling Harry especially was still on thin ice from all his antics last term. His story of a mirror that could show you your heart's desire was intriguing, though, if a little creepy. Knowing Harry's history, Hermione had to agree with Professor Dumbledore that it couldn't be good for him.

Meanwhile, Professor Vector was delighted and very touched by Hermione's gift. Mechanical calculators hadn't really been seriously tried in the magical world before, and the simplicity of the mechanism gave the professor ideas for a charmed version that could be used much more easily. In fact, she said, with a strange hint of concern in her eyes, she thought she might even be able to make it calculate faster than Hermione.

The following Saturday, they decided to try another spin in the library, but Hermione stopped them on the way out when she saw a new flier posted in the Common Room.

"What is it?" Harry asked.

"This is interesting," she replied. "Professor Babbling's giving a special seminar: 'Latin Letters as Runes.'"

"Babbling? What's he do again?" said Ron.

"It's a she, Ron," Hermione huffed, "and she teaches Ancient Runes. We should go. We might learn something useful."

"Really," Ron whined. "We're doing enough stuff already. I don't know how you manage it with Arithmancy."

"Because I don't put off everything till the last minute. Besides, Harry's got Quidditch, too, and I don't see him complaining."

Harry looked like he really didn't want to be involved in the conversation.

"But Ancient Runes is an upper-year subject," Ron said.

"'Open to all years.'" Hermione pointed at the flier. "It's probably an early introduction on a special topic—Come on, Ron, you're the one who speaks four languages."

"I speak two languages. I barely know the other two."

Hermione rolled her eyes. "Harry what do you think?"

"Uh, sorry, what are runes, exactly?"

"Runes are used for powerful or long-lasting magic. Like the charmed objects Professor Flitwick talked about, except you write symbols on them that are empowered with magic. Then, it can maintain magic without having to use your wand."

Harry's face suddenly lit up. "It can?" he said. "D'you think that could get around the rule of not using our wands over the summer?"

Hermione paled slightly and bit her lip. She had some idea of why Harry might want to know that. "I don't know," she said truthfully. "I'm not sure I'd want to try it."

"It might," Ron countered. "Lots of kids have charmed toys."

"Well, I'm in, then," Harry said excitedly. They both looked at Ron.

"Alright, I'll go if both of you are going," he conceded.

Hermione smiled and led the way to the library. Once there, Harry and Ron got back to skimming biographies, like they were doing before break, but Hermione made a beeline for the general magic section. She pulled out a very large volume that she'd skimmed earlier—one that gave an overview of many subfields of magic. Rejoining her friends at the table, she opened the book with a thud, causing her friends to stare wordlessly.

"So, uh…what's this?" Harry asked when words came back to him.

"I was thinking about checking this out, but it's kind of heavy reading, even for me—"

"Kind of?" Ron said incredulously.

"Anyway, I had an idea at home, and I wanted to check it out…" She flipped through the pages. Luckily, this book at least had a useful table of contents. "Ah, here we go: alchemy." She started reading over the page, and to her surprise, there it was, right at the top: "Wow, it really does exist."

"What does?" Harry and Ron said in unison.

"The Philosopher's Stone."

"The what stone?"

"It's a famous very famous thing in alchemy. Even muggles know about it. Here, listen to this:

"The ancient study of alchemy is concerned with making the Philosopher's Stone, a legendary substance with astonishing powers. The stone will transform any metal into pure gold. It also produces the Elixir of Life, which will make the drinker immortal.

"There have been many reports of the Philosopher's Stone over the centuries, but the only Stone currently in existence belongs to Mr. Nicolas Flamel, the noted alchemist and opera lover. Mr. Flamel, who celebrated his six hundred and sixty fifth birthday last year, enjoys a quiet life in Devon with his wife, Perenelle (six hundred and fifty eight)."

"Wow, if those Flamel people are over six hundred, it must really work," Harry said.

"Right. The book talks some more about it…it'll be small—small enough to fit in your hand. And if there's only one, then it's going to be very valuable and well-protected…It looks like there's some pretty strong limitations on its power, but if you only wanted it for yourself, it would be all you ever needed."

"Wait, so you think that's what that dog's guarding?" Ron said. "It's the Philosopher's Stone?"

"Well, we can't be sure unless Hagrid or somebody else lets it slip, but it fits what we know a lot better than anything else we've found. Some ancient artifacts would have a lot of historical value or even magical power, but none of them are anywhere near this one."

"What about the Resurrection Stone?" he suggested. "Remember? From The Tale of the Three Brothers?"

"Yes, I remember, but I doubt it really exists. And even if it does, according to the story, it's not really that useful."

"It would make sense if Snape was trying to steal the Philosopher's Stone," Harry decided. "I mean, think about it: a stone that makes gold and stops you from ever dying! Anyone would want it." He frowned in concentration. "Flamel, Flamel, Flamel…I think I've heard that name before."

"Where?" Hermione asked.

"I don't know. Something about him and Dumbledore…I don't remember where I saw it."

"Well, Professor Dumbledore teaches the Alchemy class here."

"That's it!" Harry exclaimed. "Dumbledore's Chocolate Frog card. I remember 'cause it was the first one I ever got. Dumbledore worked with Flamel on alchemy."

Hermione's eyes widened. "Then it would all fit," she said. "If Dumbledore and Flamel are friends, Flamel could have given Dumbledore the Stone for safekeeping because it wasn't safe in Gringotts."

"And the only place safer than Gringotts is Hogwarts," Harry finished.

"Brilliant," Ron said. "So what do we do now?"

"Well, we still don't know for sure that's what it is, but—" Hermione started.

"We could try to get Hagrid to admit it," Harry suggested.

"That's not very nice, trying to trick him like that," Hermione said. "Anyway, I don't think we need to do anything. I'm sure Dumbledore's keeping it perfectly safe. After all, even if Snape was trying to steal it, he didn't get past the dog."

"But if he tries again…" Harry said.

"I'm sure Dumbledore will take care of it."

"Yeah, mate, Dumbledore's brilliant," Ron said. "I bet he's got a bunch of other stuff protecting the Stone too."

"Yeah, I guess so," Harry admitted cheerily. "Well, I guess I'll have more time for Quidditch now."

Hermione silently agreed. They didn't have a definitive answer, but they had a pretty good guess, and she really needed to focus her own spare time on learning integrals.