Saturday

High inside Hogwarts a boy with a lightning shaped scar on his forehead sat on his desk, looking out the window across the landscape instead of working.

It wasn't the highest point view from inside the castle. He'd spent a full day last October trying to determine where the castle's highest point was. Finding his effort frustrated at every third turn - literally frustrated by staircases with several non-existent but visible steps that he'd nearly fallen through, and strong gusts of wind that shoved him ruthlessly but harmlessly back down - the boy decided to merely assume that a highest point in Hogwarts existed and gave up trying to find it.

Mathematically, this should be obvious. Every structure had a highest point (or points).

But this boy had encountered enough violations of supposedly axiomatic laws that he wasn't entirely convinced that two plus two equaled four everywhere in the wizarding world, much less Fermat's theorem of stationary points. Harry Potter didn't know exactly how high you could go and still be inside Hogwarts, but he was currently looking down on a flock of geese flying over the Forbidden Forest, fifty feet above the trees to avoid the Acromantula webs.

He'd created a small clearing before sitting on his desk, shoving papers aside. The clutter had grown slowly and haphazardly over the fall. Despite Hogwarts being one of the seats of the wizarding world, most of the clutter consisted of books, not scrolls. His trunks stored the vast majority of Harry's books, but he'd brought the most useful references upstairs to save himself numerous trips and those dominated the scrolls, parchments, official reports that passed from the magical government of Britain to him for review. Already read items were scattered among the ever-increasing number of bookshelves lining his room high above Hogwarts (if they possessed some redeeming value or fact Harry thought he'd need) or tossed unceremoniously into the fire place (if they didn't). Some books on his desk were those that he needed to read quickly, so that he could return them to the library before Madam Pince noticed they were missing.

It was obvious to anyone who paid attention that Harry Potter was not a normal student at Hogwarts. He still preferred not to draw attention to it, so Harry simply took the books he needed then returned them – hopefully unmissed – at a later date. It wasn't really stealing, after all. Headmaster Dumbledore had given him Hogwarts, although part of Harry knew it wasn't Dumbledore's to give. In any case Hogwarts didn't appear to mind. Still, the first time he'd snuck into the restricted section and swiped a few books from the shelves, he'd gotten a small thrill even though he knew that he hadn't broken the wards, they just didn't register his actions as theft. The wards merely shrugged instead of screaming and trapping him in an inky black tar, like they did for regular students.

Try as he might, Harry hadn't convinced Hermione to read any books from the restricted section. She'd said there would be time enough later and that she still had plenty of "good" magic to learn thank you very much and then she'd turned up her nose at him, swiveling her chair around to face the other direction and planting said nose back into the Advanced Potion Making book she was re-reading for the second time.

Harry Potter still wasn't sure if that counted as flirting or not.

Scattered in between his reference books, borrowed books and slowly growing collection of interesting magical artifacts a scroll rested. More specifically, a map. Very specifically, a magical map that accurately drew Hogwarts and its occupants then magically erased and re-draw their updated positions, as well as the ever changing campus itself. People's names appeared next to small footstep icons as they walked, ran, snuck or otherwise moved around campus. Harry had flown a broom around campus while staring at the map, but it still portrayed his motion with little icons that any illustrator would recognize as 'footprints,' despite the fact that he'd been flying and his feet never touched the ground.

The Maurader's Map intrigued Harry. It provided a reasonable and - as far as Harry could tell - true depiction of Hogwarts and its inhabitants. The question that Harry had spent a few percent of his spare time investigating: How?

As fields of science went, Information Theory had barely gotten out of diapers. Claude Shannon had figuratively conjured the entire field into existence when he published "The Mathematical Theory of Communication" at the famous Bell Labs shortly after the Second World War. Harry Potter hadn't mastered the maths necessary to fully grasp the work, but he'd read enough commentary to understand the basics of how information worked.

In Harry's brief forays into investigating the intersection between science and magic, only Information Theory had come away unscathed. Some branches of magic respected conservation laws, but generally Magic regarded Science like the boring killjoy you avoided at a party. Sometimes Magic grumbled and said a polite hello but usually Magic ignored Science and did whatever it wanted to.

Magic was Oscar Madison to Science's Felix Ungar.

But Information Theory? So far, Harry hadn't seen any magical violations of its rules.

Magic seemed to have bandwidth that, if not infinite, was big enough to not matter as a practical concern. In any case, divination didn't use much bandwidth, most spells didn't seem to use much. Transfiguration probably used the most, but estimating how much was a tricky matter. Magic had relatively good signal strength. But there was no reason – in theory – that communication channels had to be noisy. (Harry had posited that Divination's relatively useless nature was somehow encrypting information in a way to prevent noise from affecting it, unlike the rest of magic. But he had no way to test this). In any case Technology had made impressive gains on reducing noise, so magic's signal strength was not a theoretical concern.

If information theory failed, Harry suspected it would by violating the restriction on moving faster than light. Given the existence of time turners there were probably some modifications to Shannon's theory, and the possibility of sending information faster than light would be of pressing importance, once humanity spread to multiple planets. Harry hoped that magic violated that rule, it would be useful. But so far this one branch of science had avoided Magic's lecherous advances and sly come-ons. It remained pure, unbroken by magic.

That surprised Harry, but Information implies Surprise. After all, if someone told you a fact that didn't surprise you at all, you already knew it.

Part of the proof that English has redundancy built into it was that if you named the letters of a plaintext message one at a time, people could guess the next letter much more often than random chance dictated. Similarly with the words. If you asked any American to say the next word in the phrase 'The President of the United' then most would say 'States.'

"States" wouldn't surprise them. "Auto" would be surprising, except at a union rally.

As far as Harry could tell, the Marauder's Map had been the rare surprise for Voldemort during his year at Hogwarts. Not only had he not known of its existence, he'd been doubly surprised that the map printed 'Tom Riddle' for him. It hadn't shown Harry's legal name, or the name given him by his parents, or the name he called himself. It somehow knew that he was an imprint of Tom Riddle.

That was a disturbingly compelling argument for the concept of souls. Not as a religious concept but as an actual mental state, albeit only an initial state. For the time being, Harry had shoved aside the more complex philosophical questions and focused on what other information the Map could convey. It could be a profoundly useful security device. The map could detect invisible intruders – Alastor had tried a number of spells, but he showed up on the map at all times. Hermione disappeared when hidden under her Deathly Hallow, but otherwise people were clearly labeled. Harry had also wondered if the Map – which recognized Harry's origins before he had – could tell if someone was under an external influence. However, experimentation had shown that imperiused subjects were labelled as themselves, not their controller.

Harry had felt a twinge of guilt, having Minerva confiscate the Map from the Twins, although he'd at least made sure their memories were restored. But he needed to experiment with it. He'd have it 'accidentally' returned later. Even with its limitations, the Map could revolutionize security. Once Harry figured out how to replicate it, anyway.

Harry built Peverell adjacent to Hogwarts, connected at the infirmary, but it was not part of Hogwarts proper, which meant it didn't show up on the Map. Harry had wanted them separate for logistical reasons and to keep people from asking too many questions – which was another reason he'd reluctantly asked the Headmistress to confiscate the Map – but once Harry understood this device that could detect invisible intruders he'd announced that Peverell was part of Hogwarts. Then he'd decreed it. Then he'd had a law passed to that effect.

The Map didn't care, or show any of the new addition. Whatever logic it used to decide what to show, the map didn't seem influenced by politics or what people said. It didn't matter that Harry Potter felt like Harry Potter, to the map he was Tom Riddle. It didn't care that Harry called Peverell part of Hogwarts.

Harry's experiments – and thousands of galleons to pay wizarding craftsmen – had let him develop 'his' map he used for the Muggle Naval Simulation. The displaying was the easy part. He'd just gotten some computer programs to run the simulation (using thousands of dollars to pay programmers) and his map reflected the reality of the program.

But that information existed on a concrete level – on a computer monitor, or in the hard drive. Sure, the Marauder's map looked at people on the grounds. But how did it see into him? How did it see the invisible? Was it the same way that the Sorting Hat worked? Harry didn't expect an answer soon.

Good research – by definition – was full of surprises.

At this moment Harry idly studied the Great Hall. It was lunch time, which meant that most of the students were in the great hall. The sheer number of names meant that the map couldn't show them all. Rather, it could, but they'd fill up the entire Hallway with ink, so the Map didn't. Harry wondered how it decided. Did it have some intelligence, like the Hat? If so, who did it borrow it from? Or did it just work on simple rules. You could get surprisingly subtle and complex behavior from a few simple rules.

Harry had been tinkering with the map most of the morning. He was supposed to be dealing with the Wizengamot and the political fallout that was starting to happen because people weren't dying as much as they used to. Other countries were becoming concerned about their political power in this suddenly changed world. Harry wished that he'd gotten Hari Seldon when he'd recruited Professor Asimov. Figuring out the future history was beyond him, beyond anyone. So he was just muddling along, trying to smooth things out.

He'd taken a break to play with the map because he was bored and procrastinating. He'd almost resolved to get back to looking at the correspondence that had come from Casciora, a parliament of Romanian Witches, when something struck him. The students had been filing out of the Great Hall, which now was almost empty. He'd seen them streaming out through various doors, names appearing once they were far enough apart that they could be distinguished. Harry had spent the morning tracking people around, trying to think of clever security tricks or how he'd hide from the Map, if he suspected someone was watching him. If he could do that, he could return it sooner. But as he'd been thinking about this, something about the lunchtime crowd struck him. Harry pushed his glasses back up the bridge of his nose.

"Show me my room," Harry said. And the scene shifted, scrolling smoothly, and Harry saw his room, empty. Lesath was walking through the Slytherin Commons room by himself, apparently heading back to his room. Harry glanced at the clock on the wall, it was a bit after 1pm. There was a Quiddich game scheduled, Ravenclaw versus Hufflepuff.

"Show me the bleachers, Slytherin seating." Harry examined the names quickly, then shifted over to the Hufflepuff stands, just in case. Lots of people, but not who he was hunting.

"Show me the library," Harry said. Hermione was there, of course. Her unmoving name was scrawled elegantly next to her favorite table. Madam Pince and a few students, mostly fifth years, walked around the stacks. Harry studied the map for another second.

"Fine," Harry said, more to himself than the map. "Show me Draco Malfoy."

The map erased itself, just a blank piece of parchment.

"Huh," Harry said to himself, surprised.

A few minutes earlier.

A man, hair tangled in thick curls, with mutton chop sideburns steps up into the carriage, almost tripping because he cannot keep his eyes on the small step of the entrance, but is looking towards the front, at the horrific beasts tethered to the carriage that only he can see.

Draco turned his head from the window he'd been staring out of, at the front of Hogwarts and gives a slight nod to the man. "Thank you again for this, Isaac. I know it's an imposition on your day off, and I appreciate it."

"It's no trouble at all, Draco. Frankly I welcome the chance to get out and about. It's not that anyone is rude, or impolite. But I really feel like a movie shooting victim when I'm on that campus." Professor Asimov laughed and Draco realized there was probably some joke.

"I'm afraid I don't get it," Draco said. With other people he'd force a wan smile or just nod, but given the cultural differences Draco considered it better to just admit ignorance and learn from it. In this situation at least. The carriage gave a small jostle as it started off.

"Ah, a fake gunshot in movies is done with a packet of fake blood and a small explosive, referred to as a 'squib.'"

"That's actually clever," Draco said, smiling.

"Unlike the rest of my jokes, you mean?" Professor Asimov had an artificially dour look on his face.

"Exactly." They both laughed.

"Tell me, Draco, what are the beasts that are pulling this carriage?"

"What animals?" Draco said.

"They look like … two skeletal pegasus."

"Pegasus...," Draco screwed up his face, thinking. "That's a breed of winged horse, isn't it? And skeletal." Draco reached into his robes and pulled out a small black notebook, opened it, then spoke to it. "Reminder for later, research skeletal winged horses that children cannot see." The words appeared in an elegant handwriting. Draco closed the book and slipped it back into his robes.

"Quite a useful device," Professor Asimov said.

"More convenient than a scroll, but basically the same idea as a Self Writing Quill, except the spell is on the book, not the writing instrument. I'll look this up later and see what I find, although I suspect you could just ask the groundskeeper."

Draco did look up Thestrals later, his diary sketching a horrifying image. The fact this his research would take no longer than a minute was something he felt slightly guilty about, but he gave no outward sign of discomfort.

"I hope it's not much trouble but, thank you Draco. Much like this trip, which you view as a burden to me, but I'm actually happy to get out and about, and some slight errands along the way pose no real issue. I do have something for you." He handed a slim paperback book to Draco, who flipped it over.

"Nine Tomorrows," he read. By Isaac Asimov.

"I particularly recommend Gentle Vultures to you. Your speech to Gilderoy's class after that last war reminded me of the story. Not the writing or plot, but the general moral nature."

"You heard about the speech?"

"Professors Lockhart and Slughorn discussed it at some length, and in some detail. Professor Lockhart, in particular, seemed impressed with your insight and said that it showed surprising moral development."

Professor Asimov smiled as they passed underneath the gate to the entrance of Hogwarts.

Six days earlier.

Professor Asimov took one bite of Dragon Tartare and made a face. Gilderoy was still speaking "... it was gripping, as you'd expect from a Malfoy, but what astonished me was that he showed surprising moral development for a Slytherin."

"What do you mean 'for a Slytherin?'" Horace dropped his fork and leaned over, practically placing his chest onto the table. That got the attention of the entire head table, most of whom had been ignoring yet another speech by the Professor of Offenses against the Social Arts, as Professor Trewlaney dubbed him.

"Well, its just that you don't often hear about the glories of protecting the innocent and tales for the fallen from Slytherin. I mean, a speech about the nobility of those who died in war seems right for Hufflepuff."

At this moment Pomona Spout tossed her fork down on the table, which clattered loudly against her plate. "Oh, so we're victims, not like the heroic Gryffindors," she said. Professor Lockhart's smile wavered for a second, and he was about to speak when the Headmistress gently set down her spoon.

"I'm sure he didn't mean it that way, Did you?" Headmistress McGonagall cocked her head gently towards Professor Lockhart.

"No, of course not. What I meant to say. That is, the idea that good and noble soldiers die all the time is a common theme that applies to everyone. And since the outcome of the battle doesn't affect the moral nature of the combatant. Well, those facts seems like just the sort of thing that Helga Hufflepuff would agree with." Pomona sniffed dismissively, while he continued. "And while I don't think that Rowena Ravenclaw would dispute the fact that being clever in war is no guarantee of survival, I don't recall her ever saying anything to that effect."

Gilderoy Lockhart kept talking before anyone could interrupt, because he couldn't actually recall anything that Rowena Ravenclaw had ever said, and didn't want to learn at this time. In fact, he'd somewhat lost the train of thought as to why he was defending himself. After another sentence or two he remembered.

"And I'm sure that Salazar also knew what Draco said, but he didn't really emphasize it. Whereas Gryffindors have more history with heroic failure than most, because we tend to leap before we look. We don't have to dig deeply into our history to see our heroes die fairly often. Oh, we sing about the winners more than remember the losers, but the lesson is there. That's all I that I meant. Do you see what I'm saying, Horace?"

"I see you have no idea what you are talking about. You carry your simplistic view of the world and forsake nuance. Do you want to know the burden of House Slytherin? Well, I'll tell you anyway, not to enlighten you but because you deserve to shoulder the weight. We know that the dead who rot in the streets may not have been innocent, we know that you cannot reduce people to songs you sing about them when you get drunk. We know the world isn't black and white, but merely shades of grey."

"You call me a fool for seeing only two colours, then reduce it to one!" The headmistress started to speak, but Horace jabbed his pudgy finger into the puffy finery worn by Gilderoy Lockhart and poked him twice while speaking.

"Not one, infinite. You blame us for the last two decades because you are ignorant. Slytherin is the house that traditionally stops most wars. We murder them when they are babies, strangle them in their cribs or snap their beautiful necks and then go off to console their parents. Sometimes we fail, then we fight them when they are fully grown. We prefer to murder their pregnant mothers, no matter how pretty the young woman may be. And we don't go marching off with some foolish bird on our shoulder singing to us. We make hard choices, because we understand. Albus understood. He ordered people to die and did it knowingly, and it almost destroyed him. Could you do that? No, you'd just rush in yourself and fight for glory and die whether it won the war or not. Would you let Albus order you to your death? Of course you would, because you'd never imagine anything but victory and it wouldn't be prudent for Dumbledore to mention otherwise. No, the curse of my house is that we know that you cannot deal with the world you actually live in, so you tell yourself lies."

Professor Horace Slughorn shoved back from the table so violently that his chair topped over. Several students saw that, and saw his face red with rage even though no raised voices could be heard.

"Your problem, Gilderoy, is that you've only learned from your own experience. Enough to be here, but you only know Slytherins from your past. And it isn't pretty, I'll grant you. It's dark. But due to your nature you'll be outclassed by our students soon enough, because they learn from other people's mistakes. That's why you can't conceive that Draco Malfoy has learned the wisdom of war without having ever been in a real battle, because you've never learned anything by thinking and you can't imagine we Slytherins do."

As Horace Slughorn stormed away, meal uneaten, it occurred to Gilderoy Lockhart that he'd never seen a Slytherin get truly angry before.

Author's Note - If you haven't left a review on , please consider it. I'm getting paid in ego.