A/N You should know the drill by now. It's in Chapter One.
THE BURGLAR WHO STUDIED SPINOZA
Harry went to the hole-in-the-wall again, after the meeting, and back in the squad room, Detritus was waiting for him. "So youse is my new pardner," the troll said without preamble.
"I guess so, Sergeant," Harry said.
"Dat's fine," Detritus said. "I's like workin' wit new peoples. We gonna go thru th' university?"
"Just there, I think," Harry said. "We'd better let Stibbons know we're coming, I guess I could send them one of those clack-things." His hand strayed to his pocket for a pen, when he encountered the PDA. "On second thought …"
He flipped open the PDA. The imp squinted back. "Can you connect me to Ponder Stibbons?" Harry asked. The imp shrugged. "If he's in with Hex, I reckon," and then pulled some microscopic levers.
The disembodied voice of the thinking machine came through the PDA. "I understand you wish to speak with Mr. Stibbons," Hex said. "He is currently in the library with the Librarian. I will get a message to him that you wish to see him."
"Oh, right," Harry said. "I guess we could…" his voice trailed off as he looked at Detritus, whose face was a crater of thoughts-in-process. Much the same as a glacier is a canyon-in-progress.
"Whose is you talkin' to?" the troll demanded.
"Its …" Harry didn't actually know who - or what - Hex really was. "An entity at Unseen University."
"Well, tell this Anne that we is coming right now," Detritus said. "You heared that, Anne?"
There was a slight pause. "We await your visit, Sergeant Detritus and Constable Potter," said the voice of Hex. The PDA stopped glowing.
Harry stared. "You don' give wizards too much time," Detritus said. "Otherwise, you got to wait for them to finish eatin' and it takes too long."
"Okay, I guess," Harry said. "By the way, who is Anne?"
"Anne? Dat's who you is talkin' too," Detritus replied.
"I … thought I was talking to Hex," Harry said.
"You said you was talkin' to Anne Nitity," Detritus said. "Never met her. I gues she's new."
Harry sighed. "Let's go, shall we?"
Harry and Detritus trudged back down the soggy streets of Ankh-Morpork to Unseen University. Despite the trolls' near four-foot height disparity over Harry, he noticed that the two of them shared the same, well-worn, Watchmen's gait, emphasizing comfort over speed. This ensured they stayed in fine lockstep all the way to the university.
They reached the gates, which swung open for them soundlessly, and closed back, and they returned to the High-Energy Magic building.
Mr. Stibbons was slightly breathless. "Don't waste much time, do you?" he complained. The wizard turned his attention to the students, who were studying the color-coded thaumic chart. "Mr. Turnipseed, and Mr. Cottonmather. Please retrieve a block of the super-cooled ice, and place it on Sergeant Detritus' head."
The troll sat down in front of the chart, and the two students quickly came with a sizable block that they sat on Detritus' head.
"Right, everyone, that's it for today," Stibbons said. "And no sneaking in to download naughty parchments on Hex via L-space. If I find out who is doing that, it's expulsion."
Amidst a quibbling of 'it's not us, it's the Dean,' the students left.
"Right, Mr. Potter, now what is it?" Stibbons said.
"Er, first, why the block of ice?" Harry said.
Stibbons looked at Harry impatiently. "Trolls' brains are made of silicon. When cooled, the silicon vibrates faster, allowing greater and deeper range of thought. Since your partner is here, we might as well get some thought out of him.
"Now, let's get up to speed. Hex, open a channel to Rincewind, will you?"
There was a pause. "What is it?" came a sleepy voice.
"Rincewind, I'd be worried about interrupting your beauty rest, save for the fact that you have no beauty to rest," Stibbons said. "Potter is here. What can you tell us about the thaumic signatures?"
There was some disembodied muttering. "Well, I think it's a Roundworld wizard," Rincewind said moodily. "But there aren't any journals or books on the thaum, or on thaumic trace, here at Hogwarts. I don't think that wizards here have begun to recognize thaumic patterns. Even the most advanced of their arithmancy texts doesn't cover it. That's making it hard for me to see what a thaumic signature would look like from this side. I've been catching little glamours, things I can trace, to see if I can generate a thaumic field, but no luck so far."
"Hmm…" Stibbons stoked his chin, wishing for the umpteenth time he'd been able to grow a beard, so that at least he would look dignified. "Well, Harry?"
"Professor, perhaps it would be best if you could show me some thaumic signatures on this chart, so I can get an idea of what to look for," Harry suggested.
Stibbons sighed and walked up to the chart, which was full of multicolored lines and dashes. Dates ran across the bottom axis and a scale was on the right axis. Harry noticed, now, that the chart was attached to two polls, which scrolled across, so that parchment moved as the chart kept current, but it could be rolled back to see previous positions.
"Here's your spike," Stibbons said. "This was the one soon after your arrival. See the date, here, at the bottom? Your spike is a mix of blue and ocatrine, with a little greenish hue. It's quite high - nearly 7,700 thaums. Very few wizards here are capable of generating that level of power just by force of will."
"And every single wizard and witch known are mapped by their signature?" Harry asked.
"Well, not every one," Stibbons admitted. "But still, we can guess at most of them. Look down here for instance," he said, and flowed the chart so the scale suddenly read in the hundreds, rather than the thousands. "See this brown and violet? Notice it's nice and smooth, rather than spiky, like yours? That's Esmerelda Weatherwax. No doubt she's using her borrowing magic. I don't have to run any tests, I just know it's her since I've seen it so often I know it like that back of my … hmm, that's strange."
"What?" prompted Harry.
"She's drawing at least twice the normal power she usually does when she's borrowing," Stibbons said. He thought for a moment. "Oh, well, she's probably teaching young Tiffany Aching borrowing. I know that Miss Weatherwax has wanted to teach someone the magic for some time, and Tiffany's just the right age. In any event, these little traces down here are some of the other Lancre witches. Brown, with some violet. This one is definitely Perdita Nitt."
Harry took this in. "So what are the strange thaumic patterns?"
Stibbons rolled the chart back. "The first one, many months back now, you'll see is a thaumic spike at nearly 59,000 thaums. That's massive. In fact, it's off the scale. So much off the scale that we can't show the spike. You can see we have part of it, but no more, since it ran over the meter. It could even have been 90,000 or 100,000 thaums, we don't know."
The patterns were in a loathsome chartreuse, with a dash of hideous beige. They were the types of colors that would normally be chosen by the interior decorator of hell for a truly repugnant style of window-treatment.
"Now I'll alter the scale a bit, so we can see this same type of spike. Five of them, all together, all in the 12,000 thaum range, same color, same spike signature," Stibbons said.
They looked at the chart. This is where Hermione is home, thought Harry. She'd read this and immediately see the connection-
"The temple attacks," came a rumble.
Harry looked at Stibbons, who looked back at Harry. Then they both looked at Detritus.
"The thaumic pattern you are indicating corresponds to the dates and times of the attacks on the various city temples by the Grave Gourmands," Detritus said.
That does it. I'm putting a permanent freezing charm on his head, Harry thought.
"It's the Dark Mark," Harry said aloud.
"The what?" Stibbons asked.
"He's right," said Harry, growing excited. "It's the Dark Mark."
He was beginning to see the allure of charts that had long ago revealed itself to people like Hermione Granger, and other children, who go on to lives as weatherpersons or economists. On a chart, you could track an idea down, stick a pin it, and leave it fluttering like a wounded butterfly … but unlike the butterfly, you could pull the pin out, and the idea would get up and fly for you again, so you could pin it down and watch it in a different position. In a sense, it was like saying Riddle's name - it made it that much easier to think you could defeat him. People got all caught up with "oh no, it's LORD VOLDEMORT who is after me!" But they never got so fussed over, "eh, just smelly ole Tommy Riddle again, the cheeky bugger." You could smack Tommy Riddles out of your life like an aggravating gnat. Lord Voldemorts were tough. But on the chart … reduced to simple mathematical patterns, they were stripped of their outer vestige of superiorness and left as a line. A line that you could erase.
"Hot damn, Detritus! Right on," Harry said.
"Cool," corrected Detritus.
"Would you mind explaining what all this is about?" asked Stibbons.
"Okay, the Death Eaters … the Grave Gourmands, whatever you want to call them," Harry said, impatiently in a rush now. "When they attack something, they leave a mark. Their calling card, if you will. It's a symbol of a human skull with a snake coming out of the mouth. We call it the 'Dark Mark.' When they would attack someone, they would end the attack by destroying the home or building and then use a spell to cast the Dark Mark over the area, so people know they've attacked it. That's what this is. It's a record of a wizard using the Dark Mark."
Stibbons considered this. "So your theory, then, is that the previous high-thaum spike was of a Roundworld wizard somehow making his way to Discworld?"
Harry was a bit disconcerted that Stibbons had figured it out so quickly, but nodded approvingly. "I think it's the only theory that fits," Harry said. "But I don't know how they got here. When we took out Voldemort, the leader of the Death Eaters, certainly some of them escaped. We never did round all of them up - about 10 made it out on the loose we knew of. Voldemort dabbled in all sorts of magic, so it's possible he learned of the Discworld."
There was a silence. "Anything else on your end in the library, Rincewind?" Stibbons asked.
"Not such as yet, no," Rincewind said. "So far as I can tell, there is no L-Space opening emanating from the Hogwarts library. It's certainly possible to use L-Space to get into the library, but I'm almost certain it would be a one-way trip. I can't see any way out from here."
"What's L-space?" asked Harry.
"Well, a bit hard to explain," Stibbons said. "Rincewind? You're the librarian here."
"Mmm. Harry, knowledge equals power, right?" came the disembodied voice.
"Okay," Harry said.
"And power equals energy. Energy, via the theory of relativity, equals matter, with a bit of help from the speed of light. And matter equals mass," Rincewind finished. "This is the L-space equation. What it means is that if you aggregate enough books in one place, you can bend the space-time continuum. A library is the perfect place to create an L-space node. Senior librarians or careful readers can use the nodes to travel from library to library, all across the multiverse."
This was too much for Harry. "I'm sorry, but do you mean that if I just read enough in the Hogwarts library I could travel through different worlds and dimensions?"
"Precisely," Stibbons said. "Good literature can take you anywhere. In this case, however, and in the right conditions, even one word is enough, if there is enough belief. Unfortunately, or rather fortunately, Roundworld does not have the right conditions."
"Because magic works differently there?" Harry asked.
"Perhaps," Stibbons said. "I've never detected deitygen or imperativium in even small elemental form there. Here on Discworld, those elements are vital constructs of belief, which is how things run."
There was a general silence as the four - plus Hex, of course - absorbed this.
Harry shook his head for a minute. Deitygen and Imperativium … those were too hard to grasp. He went back to the physical reality of the chart.
"Okay, so why are they attacking temples, then?" Harry asked. "I mean, the Death Eaters never did anything like that on Roundworld. Oh, they went for high-value, publicly visible targets, all right. But never temples."
Stibbons looked disappointed. "I was hoping you were going to tell me that was exactly what they did do. But even so, these aren't major deities. The attacks are all on small gods. Not the big players."
Harry considered this. "Well, who are the big players?"
To their surpise, it was Detritus that spoke. "In terms of followers, Om, the Blind Io, the Lady, Fate and Offler the Crocadile-headed have the most followers on the Disc," the troll said. "There are many, many minor gods, that spring up when the requisite amount of belief is generated, and also that die out, when there is no longer belief to support them. A god is numinous only so long as there is sufficient belief to support it."
There are many things that can trigger memories. Smells, in particular, are closely associated with memory, such as, "ye gods, it smells just like the last time that someone forgot to take the trash out." But some words can trigger memories just as effectively. Fortunately for Harry, the key word here was 'numinous.'
It had been about three years ago, and it had been an Unusual Saturday. Unusual in the sense that neither he nor Hermione had any plans whatsoever. Being an Auror was a full-time job that precluded the concept of weekends, since the bad guys tended to view them as work days. And Hermione's constant experiments often meant she was on call, normally to put out the fire. But this Unusual Saturday …
This Unusual Saturday they both had completely free. It was Harry's idea that the day could most profitably be spent by sleeping in till 1 p.m., heading down for a pub lunch at 1:30, and then making it lazily back to catch the end of the quidditch on the Wizarding Wireless.
Hermione, on the other hand, had enrolled them at a muggle 'Working Day' at the British Museum. They would attend a six-hour series of lectures on the topic of Chinese mythology. Harry had realized, somewhat belatedly, that if you are in love with someone, you will sometimes do very stupid things for them.
In this case, the stupid thing to do would have been to sleep in, get drunk, and listen to quidditch. So he didn't. Instead, he went with Hermione.
To his surprise, he enjoyed it. The lectures were fascinating, the professors - from many lofty universities around the world - were engaging and brought interest and humor into their talks. Augmented by the collection of arguably the greatest museum on earth, it was a startling revelation to Harry that learning could be fun.
By far the most interesting lecture had been made by a fellow from Surrey, who although not a professor, had lived in China for 30 years and was as learned as anyone. This man collected dead gods.
" 'When a god loses his numinous power - that is, his power to be effective and cause fortune for his followers - that god begins to suffer. Fewer people believe in the god. Eventually, the god is fired. The statue of the god is removed and discarded, and a new god takes his place. The old god is no longer believed in, and a new god is necessary. This belief requires a new temple, a new statue, and new rituals,' " the man had explained. He had gone around collecting the statues of the dead gods, which now anointed his garden inasmuch as some muggles collected lawn gnomes. Harry had reflected that if Mrs. Weasley had gone round to his house for tea, she'd have fainted dead away.
He had been dwelling in a reverie over this memory for so long that Stibbons had to physically tap on the shoulder.
"What?" said Harry, jumping.
"Care to share what you're thinking?" Stibbons asked again.
"I'm thinking about dead gods," Harry said. "What is the net result of the smashing of the temples? I mean, the really big gods, probably, it would case public outcry and then there would be a rebuilding campaign and the temple would get re-dedicated.
"But the smaller gods … people would stop going to the temple, since it's burned down. Maybe they would join another temple, maybe they would believe in another god, but probably … it would be apathy. They'd forget about dealing with the gods for awhile, until some big event came along. If you knocked off enough small gods, would that create an available pool of belief?"
Stibbons was writing, furiously, in a notebook. Rincewind's voice came through the wires again. "I've been to Cori Celesti, the home of the gods," he said. "I think your theory is possible. Lots of gods get created every few seconds, but because there isn't a sustaining amount of belief, they vanish back into the mists, and the excess belief is returned. If you knocked out enough small gods, yes, I reckon you could generate a belief vacuum."
"But who would want to create a belief vacuum? You'd have to fill it," Stibbons said. "Would the Grave Gourmands really want to create some kind of new god?"
"Perhaps they are merely attempting to control the excess belief," said Detritus. The ice had nearly melted away now. "Maybe it could be parceled and sold for profit to the major gods."
"That's possible," Stibbons said. "Possibly. It would very quickly get them into high stead with the major gods, who would covet that extra belief, and further cement their power."
Harry wasn't quite thinking that. "I'm not so sure," he said finally. "I keep thinking there's something more, something we haven't seen yet. But this is the furthest we've gotten so far."
Detritus stood up. "Then we better get back to the Watch house," he said. "I's got a feelin' we got to get on patrole."
Harry looked at his sergeant sadly. "So when the ice melts …"
Stibbons nodded. "He used to have a hat which kept his brains specially cool. It was designed by a dwarf who was his first partner, I understand. But his partner was killed in the line of duty, and he swore he'd never wear another."
Harry nodded. He understood the fierce devotion you had to your partners. It was part of what made you a Watchman. It was most certainly going to be part of what he incorporated into his being an Auror. Harry reflected he might not have been the best partner his various Auror colleagues had had in the past. That, he thought, would have to be made up for.
"Right, sergeant. Back to the Watch, then," Harry said.
The sergeant nodded towards Stibbons. "Bee seeing u, sah."