Please be aware that I have taken liberties with the geography of Oxford. The wonderful wall is no longer completely encircling, and never included the tributary of the Thames, the 'Isis'. I would really like to hear everyone's opinion of this chapter as it contains only one of Rowling's creations, the rest are mine.

Chapter Seventeen

The Gleaming Spires

Three communities lived side by side in the City of Oxford. First there was the 'town': the locals who ran everything from buses to shops, industry to libraries. These muggles were the blood in the system, the cars on the roads, the supporters in the stadium; vital and necessary to keeping the city living, breathing, working. Then there were the academics, the 'gown' side of Oxford, those who made the university possible. Academics and administrators, students and dons, they made the city what it was; a vibrant learning centre with traditions dating back almost a thousand years.

Within this collective of colleges there lived a third community, one which you wouldn't notice unless you looked for it. Gandr College. The beating heart of magical Oxford. It had existed as long as the walls that encircled the city, a bastion of knowledge, debate and wisdom. A place where the questions asked would take a lifetime to answer. Its tendrils had spread throughout the University, making it impossible for the Masters of the muggle colleges to ignore. Indeed, the Secrecy Act had been waived when it came to the Masters, lest incautious students end up exposing all.

And so, on the banks of the winding Thames, the City of Oxford sat with gleaming spires looking out over the world. From the high peak of St. Mary's Church a distant burnished shine could be seen. In the Master's office in Gandr College a message was delivered, and in a sheltered courtyard two Aurors popped into existence. Oxford's calm was about to be broken.

Channels between the muggle and magical worlds flooded with messages. A decision was taken. Gates were closed, and on the radio the muggles heard the news. The centre of Oxford was to be isolated due to IRA activity. The wizards heard a very different story; the elves had come and now was the time to defend the city. Though not all seemed to understand the gravity of the situation.

XoxoX

In Gandr College there was a room with a beautifully patterned carpet to compliment the wood-panelled walls and exquisite paintings. Sirius tried not to pace across it as he waited, but it was difficult. It had been impressed upon him how important the information he'd been sent to get was. Even the Minister himself had spared time to speak with him, which made Sirius rather edgy.

It was understandable that he jumped when the door opened.

A thickly robed, slightly portly gentleman entered with a jovial smile despite the circumstances. "Ah, hello. You'll be the Auror?" the man said, lowering himself into one of the comfy chairs.

"Sirius Black, sir," Sirius replied, taking the seat opposite him.

"Eric Swanbank, Dean," Swanbank shook the young man's hand and summoned tea.

"Thank you for seeing me on such short notice and under the currant situation, Mr Swanbank," Sirius said, placing rather more than his usual number of sugar cubes in his tea.

"Dean, if you please. No problem at all. We are the world-class wizarding University after all. I'm sure we can solve this little elvish problem in no time," The Dean smiled and selected a nice piece of shortbread.

Sirius blinked rapidly and leant back saying, "You do realise that the city is surrounded by something in the region of two thousand elves, Mr Dean."

"Dean, just Dean. I know this must be hard for a non-academic to understand," Swanbank patted Sirius's hand sympathetically. Raising an eyebrow he went on, "Surrounded you say? Well, we have the finest minds here in Oxford, I'm certain it can be sorted out in short order. I have no worries."

"There's at least six thousand more out there, sir," Sirius persisted.

"Goodness," Swanbank said without losing his genial smile, "I suppose that's why you've come to me. What exactly can the gleaming spires to for you?"

"Well, I, we need to know how to kill them, Dean," Sirius sputtered, derailed by the Dean's nonchalant attitude. If he didn't take action then his precious 'gleaming spires' of Oxford would be under elvish rule. Its people, academic and non-academic alike, would be killed or enslaved, and this portly fool would have to lose that smile.

"Kill them, hey? I can't answer that without data, can't answer anything without data! Haha! What's worked then, dear fellow?"

Cringing slightly at the endearment, Sirius answered, "Only physical means and Elemental Spells have had any effect, Dean."

"Elemental spells, hmm, requires a detective," Swanbank tapped his teaspoon on the side of his second cup of tea, "They are in the class of Dynamics, so...Yes. You need to see Archie Fothergill. Across the quad, straight up the stairs, third door on the right. Second floor."

Sirius stood as Dean Swanbank did and found himself ushered, almost pushed, towards the door. There the Dean pointed him in the direction of the nearest stairwell and shut the door firmly behind him. Sirius shook his head in amazement, some people couldn't take hearing about the bad stuff, dire situations, and would get it out of their lives as quickly as possible. It was a nice life but, damn, if they weren't lucky Sirius and his ilk were around to keep it that way.

XoxoX

Near the Water Gate on the Thames Archibald Fothergill, Professor of Dialectics and Dynamic Spells, stood with his fellows and watched as the river's defences were tested. Students in punts went up and down before them, shouting various incomprehensible figures back to the learned scholars. Every now and again a carrier pigeon would drop down in front of one of the Dons and a murmur would run through the assembled as the information was passed.

"Kidlington's fallen," said Joseph Cinerea, Professor of Illogical Mechanics.

"Ah. Any news on Wheatley?" Archibald asked.

"Took it an hour ago, old boy. Didn't you hear?"

"Then it appears they have effectively severed our communications network."

"Looks that way," Joseph said a little too cheerfully. "Say, isn't that one of your boys?"

Archibald out over towards the Mound and saw one of his PhD students running across the sward, robes billowing. He puffed over to the river bank, and hurried along the path to his Professor, apologising to a group of dons he barged through.

"Bennett?" Archibald questioned as the young man got his breath back, "Elucidate the reason for your present condition."

"There's an Auror here to see you, sir. In your office," Bennett choked out between breaths.

"Most irregular. Come along, Bennett." Archibald strode off, nodding to colleagues, his poor PhD student carried along in his wake.

XoxoX

On the west quadrant of the walls gathered the staff-men, those wizards who researched the advantages of using a staff rather than a wand. Right now they were finding a six foot length of oak over the head of an elf was very advantageous. They were using them for magical purposes too; fireballs were sizzling out over the wall to impact amongst the streets and houses, keeping the majority of the elves at bay. Those who did venture close enough to scale the walls had to deal with slick ice and, at the top, a swift bop on the head.

The wizards didn't have it all their way, however. Not only did the elves have greater numbers on their side – only some hundred and fifty wizards lodged within the walls of Oxford – but they also were deadly accurate with their light spears. Any time a wizard popped up to see where to launch a fire, ice or wind spell, half a dozen spears clattered around, and through, him. A variety of shielding spells had been tried and discarded, the spear heads of bronze cutting right through like a warm knife through butter. Some of the more enterprising young student of magic had even 'borrowed' dustbin lids to use as makeshift shields.

Edward and Alec Grey were taking it in turns to look around the crenellation they had taken refuge behind. From their placement near the centre of the wall, between two gatehouses, they had plenty of targets to aim at. Alec, the elder, ducked a well-thrown spear and dropped back behind the wall.

"Your turn," he gasped, "Aim right."

"Your right or my right?" muttered Edward, hefting his staff. Jumping up he aimed and shot off a bolt of smoking fire directly into the path of the line of troops his brother had spotted. He ran his eyes over the pock-marked line at the outermost range of spell fire, and blasted another creeping elf with a fireball before dropping back down. "Is it just me or have things got quieter in the last ten minutes?" he asked.

"It's you," responded Alec automatically.

"Seriously."

Alec paused in his crouched position and stared at his brother's cocked eyebrow - he must have caught it with fire at some point as half was missing. Silently Alec noted that fact so he could tease the first year student about it later, then he looked up the line of the wall. There were less staff-men standing than when he last looked. Then again there were less men full stop. Even so, perhaps Ed was right. He glanced down the other way and listened.

"I think you're right," he said. He couldn't hear as many spells being fired.

"Do you think-" began Edward only to stop short as a head appeared in the crenel behind his sibling. Grabbing Alec's singed shoulder Edward pulled him down and launched to his feet.

He batted away the sword swung at him and rounded his own weapon at the elf. With a hefty blow the solid oak connected. A satisfying thunk resonated up the staff and Edward stepped back ready to swing again. The elf, winded, moved into a fighting stance and, wielding his sword with a cry, attacked. Edward took the staff in both hands, using it defensively to ward off the stinging blows. Slowly he was driven backwards, constantly fearful that his next step would land on Alec. Then, like a light in the dark world of raining attacks he heard a whisper.

"Duck."

He ducked. Over his head came whistling his brother's ash staff. It hit the elf in the side, throwing him from his feet and off the narrow walkway. For a second the soldier windmilled in midair. Then he plummeted. Immediately both brothers ducked to lie flat on the stone as spears flew over head. Two sets of eyes tracked the elf's fall and two faces winced as he came down right on top of some pointed railings.

"That's got to hurt," Alec commented blandly.

"I'll say," rejoined Edward. "Er, thanks."

"Add it to the list," shrugged Alec. "You're going to owe me a keg at this rate."

"We'll see. Hey is he supposed to be that colour?" Edward pointed down to the impaled elf. Spreading from the iron railing across his body was a strange purple hue. It was like someone was pouring dye into his body.

"That's new," agreed Alec.

XoxoX

Hardly had Sirius been introduced to Professor Fothergill when a gangly young man knocked on the doorframe and told them they were wanted in Autopsy. Apparently some of the wizards on the walls had got lucky and landed the medical team with a specimen to dissect.

As they walked through the narrow back streets and through arched doorways Sirius commented on the Professor being summoned for an Autopsy.

"It's because he'd Professor of Dialectics as well as Dynamic Spells, you see," answered the helpful Bennett.

Sirius nodded automatically, he could see a headache looming in his future with all the academic terms. Deciding he didn't like the future much he turned the nod into a shake and complained, "No. I don't see. What on earth are Dynamic Spells, and what's a dialectic? Why can't you people talk normally?"

Bennett laughed quietly and confided, "I was the same way when I arrived here. Six years later and its second nature. Basically Dynamic Spells are Charms, and a dialectic is an investigation into the truth of opinions or a logical discussion of ideas and opinions." Seeing Sirius's continued blank look, Bennett licked his lips and tried to simplify further, "He's an academic detective."

"Ohh, right," Sirius smiled, nodded, and held open the door of the building for his new best friend.

Inside two young men, clearly brothers from the similar noses, were being grilled by John Smith, the other Auror who'd been sent to Oxford with Sirius.

"So you just hit him with your staff and he landed on the iron railing?"

"Yes sir," Alec Grey replied.

"Sirius," greeted Smith, seeing him enter. He held out his hand to be introduced to the men accompanying the younger Auror but as he did the double doors behind him swung open. He turned and smiled at the green-gowned woman who came out, stripping the gloves from her hands.

She took in the collection of people waiting for a report on the body lying in her morgue and singled out the one person she recognised.

"Detective Smith, that is one very strange creature in there," she said, pointed back to Autopsy.

"Do you have an explanation for the colouring?" Detective John Smith asked, "And a cause of death?"

"Aside from the iron pole through his chest?" Sarah responded. She threw her gloves in the bio-hazard bin and said, "In medical terms he's been poisoned – systemic failure through inhibition of cardiopulmonary function."

Nest to Sirius the Professor nodded and hummed, pulling out a notebook from his robes and a pencil from behind his ear.

"And that's the reason for the...purple?"

"His system looks as though it's copper-based rather than iron," Sarah sighed, this was going to one mess of a report, "From the way the colouring graduates it looks as though he's been poisoned by the iron railing, but since he was already dead and metal poisoning takes considerable time I'm not going to hypothesise," she threw up her hands.

"Excuse me, but did you find stratification or sedimentation?" Fothergill asked, his pencil hovering over the page.

"Neither. Quite frankly this is the strangest homicide, the strangest creature, I've ever autopsied," Sarah replied. "If I was forced to comment I'd say that the iron bonded with his blood and stuck in his heart, causing it to fail. The colouring was probably to do with that. But with such a short time to do this, and no toxicology available because of the bomb scare..."

"Thank you Sarah. I'll keep you informed," Smith said, turning to herd the wizards from the building.

"You do that."

XoxoX

"This is good news isn't it?" Sirius asked as the two Aurors and four Academics settled into Professor Fothergill's office. "We can conjure iron things to fight, sit back and enjoy the show."

"Hardly!" scoffed Archibald, "To enact a sub-structural persistent morphic to constitute iron is an egregious idea."

Sirius blanched at the tone and turned to Bennett for a translation.

"It would be a bad idea."

"I got that bit, but, why?"

"The morphic properties of iron are ameliorated by the sub-structural transformation caused by successive annealing during the forging process," said Archibald, pulling books from his shelves and comparing pages to his notes, "Where did I deposit Mollington's – ah ha!"

"Railings, horseshoes, all the things that would work, are forged, and if you forge iron it makes it harder to do magical things to it," explained Bennett.

"You understood that?" muttered Sirius, turning as he was tapped on the shoulder.

"If you're alright here, I'm going to take these boys back out to the wall. I'd like to see these elves for myself," John Smith said, indicating the Grey brothers who had finished wolfing down some much needed lunch and were now looking a little bored.

Sirius nodded and waved his hand in assent. He may not understand what the Professor was blathering on about but with Bennett translating he was getting the gist. He only hoped he could come up with some half-decent questions that weren't too stupid. He turned back to Bennett and asked, "If you can't conjure it, what can you do to it?"

"Professor? Am I right in thinking Dynamics would work?" Bennett said, interrupting Fothergill's quest for knowledge.

He stopped and stared at the far wall for a moment, apparently examining an excellent watercolour depicting a sailing ship on high seas. Then he hummed and said slowly, "The only spells which would produce viable results are those who composite dynamic encapsulates the object rather than penetrating the core and producing a fundamental shift in the morphic field. So, yes." He sniffed and pulled another book off the shelf, flipping to the index before plunging into its depths with a satisfied noise.

Bennett turned to the blank-faced Sirius and said, "Charms would work but, uh, transfigurations wouldn't."

"Okay," Sirius acknowledged. He then held up two fingers and said, "I have two questions. One: what would happen if you tried to transfigure iron? And two: why don't you call them Charms?"

Fothergill tutted from his desk and replied, "Morphic spells, or transfigurations as you say, would cause a class one dispersion of the object over a geographic equidistance, often with removal of vitality within a certain proximity. As for your second question; Bennett, you deal with the first year students, I'm certain you've encountered this inconsistent view before."

"What?"

Bennett patted Sirius on the arm and handed him a biscuit. "Basically if you use a transfiguration on iron then you'd end up with the object exploding and killing people. Your people."

"Right, yes, but what did he mean 'inconsistent'? My view is very consistent!"

"He didn't mean it unkindly," Bennett said with a small smile. "It's just, um... You know in first year of school you're taught one view of how magic works?"

"Yes," Sirius said, suspicious that this was going to lead him to something he didn't understand.

"And by seventh year you're taught an entirely different view?"

"Yes."

"Well, in University you're taught that nothing you were taught in school is actually correct. Magic is a far more complex thing. And, uh," Bennett waved his hand towards himself, "by the time you get to PhD you have high-level dynamics, low-level dynamics, and quasi-morphic dynamics. It's all a bit complicated."

"Clearly," sighed Sirius. Suddenly he wished Remus or Lily were here, he was sure they'd be able to understand all this stuff a lot better than he was. He tried desperately to summarise what he'd deciphered, "So forged iron is resistant to magic, transfigurations would blow it up, but charms wouldn't. And I know nothing about magic."

"Yet you're the one who's been holding off the Dark Lord while we've sat in our ivory towers," mused Bennett, "Yes, everything you've said about iron is correct. What I don't understand is why iron poisons elves. Professor?"

Fothergill slammed his book closed and scowled at it fiercely. "Nothing!" he exclaimed, "Oh, there are references in Mollington and Banastre, even in Lucian, and all agree: iron and magical creatures are fundamentally incompatible. But as to why? Nothing."

"It will work though, won't it? Attacking with iron will kill them?" Sirius asked worriedly.

"Oh, yes. The iron undoubtedly needs to enter the bloodstream for poisoning to occur. Touching the skin will burn but not kill them."

"Right. Good," Sirius sank back in his seat, relived.

"Professor," Bennett said, frowning as he recalled a discussion from his third year, "Surely high-level dynamic spells would broach the spacial net of the object producing disturbance in the flux ratio?"

Sirius looked at the PhD student in surprise. It seemed he could speak the academic language as well as the Professor, though what he'd said was bit of a mystery. Across the room Archibald began to laugh.

"Only if someone were stupid enough to use vitality based dynamics on a non-vital object!" he burst out, and shook his head. He turned away to gather his notes, still chuckling to himself.

Beside him Bennett smiled sheepishly until Sirius raised an inquiring eyebrow. "Using cheering charms on a rock is dumb," Bennett muttered.

"Ah," Sirius uttered, hiding his own smile. Even he knew that one.

XoxoX

While Sirius was debating the finer points of iron, John Smith and the brothers Grey had ascended a steep flight of stairs and entered a small stone room. The room was right above one of the very shut gates and contained half a dozen wizards and a few old arrow slits. Every now and again there was a desultory clatter as a spear was thrown at the narrow gaps.

A couple of pale-faced first years moved out of the way as Smith peered through and out to the elvish-taken city beyond the walls.

"You should be able to see the barricade down the main street from here," Alec said.

"What the muggles are doing we've no idea," added Edward, "But if they've got any sense they'll stay out of the way of our fireballs."

John could see the barricade – a sturdy wood and pilfered stone line behind which the occasional flicker of red hair and bronze helmets shone. He looked round, down the line of houses and road systems, across the pot holes and melting ice, and couldn't see the end of the elves. They just vanished beyond the curve of the wall, continuing their siege of the city.

"They're not venturing close," he said.

"Heh. Watch this," said Edward, and he motioned Smith out of the way so he could aim his staff through the arrow slit. With a whispered word a cold white light burst from the carved end and hurtled towards the ground. It impacted with a crackle and ice spread fast over a fifteen foot radius from the centre.

There was a moment of visual distortion then five sliding elves appeared near the edge of the frozen ground. They looked quite amusing, trying desperately to keep their balance on the ice as they hurried away from the site and back to safety. They weren't quick enough though as fireballs came hurtling from all quarters to catch them as they ran.

Smith stared from the window, impressed and a little disturbed. He took his mind off the sight below by asked quickly, "Some type of camouflage I take it?"

"A very sophisticated type of camouflage," Edward agreed.

"We just keep firing and keep both eyes open for when they reach the wall," Alec said.

"And the wall's solid? Continuous?"

"The gates, and where the Thames enters and exits, but the Spiritual Linguists have them covered."

XoxoX

It was dark and it was night. The battle had lasted all day and looked set to last many more. The elves had cut off all supply lines at sunset; a translucent barrier emerging from lodestones to splinch all apparators. With the floo network still down, the river routes blockaded, and gates having to remain firmly shut Oxford was officially under siege.

In a set of rooms in Gandr hall Sirius paced, still hashing out metallurgy and magic with Bennett and Fothergill. On the walls Smith had added his own wand to the fray, teaching Auror tactics as he went.

To the north-west of the isolated city a section of the river known locally as the Isis rippled its silent way under weeping willows and wooden jetties. There, lying under a solid stone bridge and towers, was an arch and a portcullis – the North Water Gate. The water flowed quietly through, unimpeded in its passage. Beyond lay reed beds, stark and still in the calm. Yet there, in the dark, a patch shifted and something descended into the black waters. Several somethings.

They moved through the water with nary a wake nor sound until they came to the portcullis. Then there was a long, drawn-out creak and groan which echoed under the arch. Heads poked out of windows above the gate, lights sent floating down to the water's edge. The groaning ceased. The lights faded away and the heads withdrew, shaking. A minute or two passed without disturbance, then there was a water-muffled pop and a series of ripples under the arch. The somethings moved on. Under the walls, down the river.

A heron stood crouched like an old man under a willow, its yellow eyes fixed on the water gate. It watched silently as the grass rustled and boards creaked; several wet patches forming on a jetty. The drips moved off, heading towards the Mound and the City Centre. The heron unfurled its neck and wings, thrust downwards and lifted skywards. It flew with clean strokes towards the old motte -the Mound – where a band of men waited around a fire.

It settled just outside the firelight and, with a shudder, old man heron became old man wizard. Joseph Cinerea strode into the circle of light and coughed lightly. Three men sprang up, challenging him with wands and amulets.

"They've breached the Water Gate; heading this way over the fields," he announced, "You'd best get a move on."

The dozen men, all now roused from half-slumber, picked up what they needed and jogged away down the side of the steep hill.

"Is there any cider left?" Joseph asked the air.

XoxoX

Sirius stood with John on the bank of the Isis, watching as the portcullis was raised and assessed. There was a man sized hole at the base, and the bodies of the intruders had all shown burnt hands. Clearly the elves had swum up, grabbed hold of the iron and pulled.

"Are you certain you have all the information?" John asked as a student dove into the water to retrieve the lost bars.

"Yeah. I'll get it to the right people. And, uh..." Sirius hesitated.

"I'll keep your secret," John assured.

"Thanks," Sirius said.

The diver emerged from the murky water, holding aloft a criss-cross lattice of ironwork. There was a hubbub from the rest of the people waiting on the banks as they helped him and his prize from the water. Several people took the iron bars and examined the ends, a muggle with a blowtorch taking particular interest.

John clapped Sirius on the shoulder and said, "Good luck." Sirius thanked him and John moved away to join the crowd.

Sirius waited until he was gone, then he stepped further back into the shadow of the willow and transformed. Sniffing the air Padfoot became aware of the city in a whole new way. The people, the river, the heron that had stood here hours ago, all became blindingly obvious to his nose. He trotted out from his tree, passing from cover to cover until he was up against the wall by the raised water gate. There were many wizards with wands trained on the area, so he slipped as silently as he could into the river and dived. Dogs didn't dive well, they preferred to swim on the surface in their charming doggy paddle, but Padfoot preferred not to be turned into a dog's dinner, so he dove under the water and swam as fast as he could.

Once on the other side he swam a short distance up the river until he reached a nice low muddy bank. Padfoot pulled himself out and shook rigorously, then, with a sniff of the air, he set off. All he had to do was get beyond the elvish lines and the anti-apparation barrier, then he could apparate to London and the Ministry. All. Padfoot sneezed. Why did he always volunteer for the dangerous stuff?

XoxoX

So there you have it. Please remember to review. Even one word would be useful. LB