Dius Corvus

Four years have passed since the War ended; twenty-seven since Jonathan Frost disappeared. Snape, no longer at Hogwarts, has learned the life of loneliness. But the past, coming from the icy north, will not leave him alone. Sequel to Tread Softly.

A/N: This follows Tread Softly, but it is not necessary to read Tread Softly to read this. To give a recap of events (spoilers ahead!), Harry defeats Voldemort in a final encounter that throws him back to the time of Severus Snape and the Marauders. He masquerades as a student under the alias Jonathan Frost. As he and Snape get closer, Harry learns that the final encounter forced his soul to merge with Voldemort's, giving him both immense power and darkness. Suffering from a sense of fatality and guilt due to crimes committed by both components of his identity,Harry leaves Hogwarts for a place of cold numbness.

Once again, many thanks to Procyon Black for her careful beta and insight on life near the pole. Neither of us is entirely certain about Latin grammar, so any help with regards to that would be welcome.

"…but now I know
That twenty centuries of stony sleep
Were vexed to nightmare by a rocking cradle,
And what rough beast, its hour come round at last,
Slouches towards Bethlehem to be born?"
- 'The Second Coming,' William Butler Yeats.

"[He had already understood that he would never leave that room, for it was foreseen that the city of mirrors (or mirages) would be wiped out by the wind and exiled from the memory of men at the precise moment when Aureliano Babilonia would finish deciphering the parchments, and that everything written on them was unrepeatable since time immemorial and forever more, because races condemned to one hundred years of solitude did not have a second opportunity on earth."
- One Hundred Years of Solitude, Gabriel Garcia Marquez.

"There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy."
- Hamlet, William Shakespeare.

Chapter 1: The Mission North

Ginny sat impatiently at the bar, fidgeting with the bracelet around her left wrist. She tried to tune out the raucous Quidditch players a few feet in front of her, who were drooling at the sight of a writhing pole dancer. It was very difficult, especially since bits of the stripper's anatomy were practically in her face. She wasn't even good-looking, Ginny thought. The men around her were under some sort of lust charm, Ginny was sure, but she wondered how the charm could make that huge, hairy mole even remotely attractive.

It wasn't the first time she had been in a den, although this one—Hell's Chateau—was a first. They had a nice exterior, Ginny decided. Flashy red lights and a compulsion spell to boot. Inside, the walls were covered with mirrors that were charmed to distort rather than reflect, and the ceiling flickered with a dizzying array of lights. There were also, of course, the requisite poufs and couches, on which lounged the potheads with what looked like rolled up bits of parchment sticking from their lips. Some, Ginny noticed, were in a catatonic state. Others, particularly on the floor behind the couches, seemed to be engaged in some very strenuous activities. Ginny hoped that they at least knew each others' names before getting down to it.

She glanced at her watch, touched her bracelet, and sighed. It was typical of her fellow Auror to be late, but not this late. Maybe something was the matter. More likely, he was in a pub, banging his tankard at the Quidditch announcements.

"Ginny! There you are, I couldn't see you through this crowd."

Ginny shifted aside to let her fellow Auror take a seat. "You're late," she accused and glanced at her watch. "Twenty minutes late."

"Sorry," Cormac McLaggen said. "Hey, a lager if you would?" The bartender nodded. "Whew. I need that."

"What were you doing?"

"Helping Francine shop."

"Aww," said Ginny, smiling, "that's sweet."

Cormac gave her a disgruntled look. "Her excuse was that I'd have to wear it. But I think she just wants to torture me. She enjoys that, you know. Thanks, pal," he said, and took a drink.

Ginny checked her bracelet again. "I'm sure that's why she said yes."

"Yeah, think so too," said Cormac, letting out a loud sigh and then a burp. "Sorry," he said, sounding completely unapologetic. He glanced around for the first time, and stopped short at the sight of the stripper.

Ginny prodded him with her wand. "Sobrius," she intoned.

Cormac jerked back slightly, then gave a sheepish smile. "Thanks."

Ginny rolled her eyes. "I didn't know you liked giant, hairy moles."

"Hey, she's got a charm on her, probably a really strong one," Cormac said defensively. He glanced back over his shoulder and turned with a rather queasy look on his face. "God, can't believe the size of the thing."

"Do you have the bracelet?" Ginny said briskly.

"Yeah." He reached into his robe.

"You're not wearing it," Ginny said, looking pointedly at his bare wrist.

"I can't wear it," Cormac complained, drawing out a small band of gold. "People would think that I'm a pouf."

"What would you have liked the D.O.M. to have made, then? A codpiece?"

Cormac may have blushed, but Ginny couldn't tell in the red-colored light. He leaned closer, and she saw his lips mutter an anti-eavesdropping spell. "Any activity?" he muttered.

Ginny shook her head. She looked around casually, making sure they were not being watched. "My bracelet hasn't gone cold at all."

"But you're sure they work," said Cormac.

"Of course they work, Hermione's the head of the D.O.M., isn't she?"

Cormac took another drink of the lager. Ginny felt a bit annoyed. Hermione had told her that it was unusual for the head of the Department of Mysteries to be a woman—there had only been two others in the past two-hundred fifty years, and one of them had been an interim head—but Ginny was surprised at where such idiocy popped up. She wondered if maybe Cormac had a personal grudge against Hermione. Ginny knew that Cormac had been two years ahead of her at Hogwarts, and one year ahead of Hermione, but other than that, she was in the dark.

They said nothing for a while, and Ginny looked around the room, hoping the sad feeling that came whenever she thought of the past would leave. The pounding thud and jerky flashes of light only jolted her uncomfortably; she wished, briefly, that she were back in her own flat, soaking in the bathtub with the sound of Celestina Warbeck crooning from the radio. It had been a long day.

"He looks a bit familiar," Cormac said, nudging Ginny's elbow. She turned to look at where he was pointing with a slight tilt of his wand. "Don't know where I've seen him before."

The figure in question was sitting hunched on one of the poufs. It was difficult to tell if it was a man or a woman, as a black cloak covered all of its features, save for the edge of a lanky curtain of hair that hung about its face. Ginny started; instinctively, she thought of Professor Snape, but what could he be doing in a den?

She started again. The bracelet on her wrist had grown cold. "It's here," she whispered, gripping her wand tightly and looking about the room.

Cormac had slipped the bracelet into his left hand and sat back, as though relaxing. "Another pint, please," he shouted.

Ginny felt her lips tugging in a grin. Cormac was very good at that. She glanced through the room, thinking fast through the blood thudding in her temples. The coldness of the bracelet sharpened to the point that Ginny knew whoever possessed the crackle was no more than an arm's length away. She glanced around her. There were several people walking in and out of the room. Whoever this was had to be walking in, she thought, her eye settling on a man who had just entered. He had the streaked party-clothes and bleached hair of most of the den's regulars, and was examining the room. Then he made his way towards the couches in the back, and Ginny felt the coldness recede.

"Cover me," she whispered and slipped nonchalantly from her stool.

Wand in hand, she forced her way through the crowd. The smell of weed had gotten stronger mere steps from the bar. Ginny caught sight of a few blank faces, whose bodies were gyrating mindlessly to the throbbing music. She suppressed a shudder; they reminded her of the victims of the War who had been Crucioedinto oblivion.

The man had stepped past the hunched-over figure and paused. He seemed to be searching for someone. Ginny smirked; it was probably difficult telling who was who when everyone was a tangle of drugged and naked limbs on the ground. She stepped forward; the cold sharpened.

Ginny nearly tossed a curse off when she felt someone grab her upper arm. "Hey, redhead," a voice slurred. "Alone here? Let's have a dance, eh?"

"Thanks, I'm with him," she said, tilting her head at Cormac, who was placidly sipping his lager.

"C'mon, just a dance—"

The man had taken something out of his cloak and, bending down, was slipping it into the back pocket of someone who was sprawled, shirtless, on the floor. Ginny wrenched away and aimed her wand. "Accio!"

The package shot into her hand, and the coldness in the bracelet intensified. This is the real deal, Ginny thought grimly. Just holding it in her hand, the actual substance separated by a layer of thin gauze, was enough to make her aware of the effects.

"Expelliarmus!" she shouted, and a wand jerked out of the startled man's pocket and into her hands.

"In the name of the Ministry of Magic, I hereby arrest you for illegal possession—"

The man bolted for the crowd, but Ginny was expecting that. "Petrificus Totalus!" The man's arms and legs snapped together and, still hurtling forward from his earlier momentum, he toppled to the ground.

One down, another to go, Ginny thought as she turned to face the man on the ground. But to her dismay, there was no one there, besides a woman who was weakly waving an empty pint while lying on the floor. Ginny cursed. She scanned the room quickly; several people had noticed the scuffle, but nobody was dashing away as though their life depended on it. Her eye caught Cormac's for a moment, but he had only a frown on his face. Not helpful, Ginny thought, turning back to the back of the room.

For a moment her gaze rested on the cloaked figure. She hesitated. Suddenly, there was a squawk, and a bare-chested man shot up from the hunched figure's feet, clutching his rear in a most ungainly fashion. Ginny aimed her wand.

"Stupefy!" she shouted.

Cormac had jostled through the crowd to her side. "Got them all?"

"Yes, two," she said, pointing to the man who was glaring from the floor. "And this." She dropped the package into the bag Cormac was holding. There was a whirring noise, and Ginny knew the package had ended up on a desk in the Department of Misuse of Magical Substances.

Cormac pointed his wand. "Funis! Loquor!" He cleared his throat. The man on the ground now had ropes strung around his body, but his mouth was no longer frozen. "In the name of the Ministry of Magic, I hereby arrest you for illegal possession of the drug cocaine, in its magically modified form, otherwise known as crackle. You waive your right to speak; anything you hereafter say—"

The man spat at them. "The White Knight will get you all," he snarled. "He'll get you! He will! The White Knight, he'll protect me!"

They were not as unnoticed as she had guessed, Ginny thought as she took in the half-turned glances they received. The name was causing even more of a reaction, hinting, she thought with a sinking of her stomach, of the effect of Voldemort's name.

"Anything you say hereafter may be used against you in your trial."

"The White Knight will get you, he'll—"

"Silencio. Ginny, hand me the other one, will you?"

Ginny levitated the limp body over a few poufs and to Cormac's feet. She couldn't resist glancing at the fellow's rear; there was a scorch mark, she saw, as though someone had lit a blowtorch there.

"Let's get out of here," Cormac said. "I don't think they've deactivated the wards yet. We'll have to take the Floo across the street."

"Yeah, you go first," Ginny said. Cormac gave her an odd look. "I've got a hunch I want to check up on. It's nothing, I'll be fine."

"Weasley," he began in the irritating voice that reminded Ginny of one of their supervisors, "we're not supposed to separate on duty…"

"You let me wait here alone for a good twenty minutes," Ginny interrupted. "If it'd been twenty five, I'd have had to take them on myself. And let me remind you of that time in Devon, it was you who told me to go on ahead because you had to check up on something. Of course, you were actually having a beer with Colin Creevey…"

Cormac's face paled. "I was just… having an ale…"

"Yes, I know," Ginny said, "but you're in no place to give me that nonsense."

"Right," Cormac muttered. He levitated the two bodies in front of him, but paused. "Look, don't mention about Colin, all right? I was just, uh, catching up with him—"

"Don't worry, I won't," Ginny said with a grin. "I didn't know you were so concerned with being a goody two-shoes."

Cormac flushed, not out of embarrassed pleasure as he sometimes did, but in the uncomfortable way that made his face look like a mottled mushroom. "Yeah," he said gruffly. "Well, I'll be gone now." Without another word, he squeezed through the crowd, the two bodies bumping haphazardly against the dancers on the floor as he went.

That was interesting, Ginny thought. Sometimes Cormac acted more than a little oddly, but that was probably due to his big head. His brash arrogance could sometimes be very trying on her nerves.

A movement caught her eye; the hunched figure had stood, and was now pushing its way through the crowd. It was already halfway through the room. Ginny plunged back into the morass of sweaty bodies; she wanted to yell something to get the figure to stop, but she had no idea what to call him—if it was a him. The music was too loud anyway, making her sternum vibrate as though struck again and again by a blasting curse.

She shoved her way finally into the street. It was night, and the cool air blew across her sweaty skin. The cloaked figure had nearly reached the edge of the Apparition barrier.

"Wait!" Ginny shouted, running forward. "Professor?" she added, more hesitantly. The figure seemed not to have heard at first, but at the second call he paused enough for Ginny to reach his side. He pulled his hood back slowly.

"Professor Snape!" Ginny felt a flush of disbelief, mixed with a pleasure that surprised even herself.

Snape took her in, crossing his arms in his old way of silencing an entire classroom, the lines around his mouth settling into a faint, familiar frown. "Miss Weasley," he said coolly, "What an unexpected pleasure."

"I didn't think it was you," said Ginny, smiling hesitantly, "it was just a lucky hunch."

"Ah," he said, looking as though he might say something snide, but seemed to curb himself. "Is there a reason you decided to holler my name?"

"Well, thanks for helping out back there. That was you, wasn't it, Professor?"

"Yes, it was," Snape said, looking as though he wished it weren't. "You need not call me Professor, Miss Weasley. I am no longer obligated to suffer the horrors of the classroom."

"You know what they say. Once a professor, always a professor."

Snape smiled thinly. "Please. I do not need to be reminded of the likes of Longbottom."

"Neville's doing great in Brazil," Ginny said, a bit defensively. "I heard that he's writing a book on Herbology, and Fred says they're thinking of using it when it comes out for the upper level Herbology classes."

"Ah," said Snape, eyes glittering. "Hogwarts seems most desperate, of late." Before Ginny could say anything, he pulled back slightly. "But I am sure it will be an excellent text. It is not difficult to believe that Longbottom has abilities that exceed his competency in potions."

A truce, Ginny recognized, just as she realized that had not really been baiting her. "I'm curious, though," she began. She hesitated. It had been years since she'd seen Snape, even longer since she'd been in his class, but he looked no less intimidating with the slightly impatient inquiry of his eyebrow. But she was an Auror, Ginny reminded herself. She looked at him more closely. At first she would say that he had not changed since that last meeting in the Order headquarters, but it was not quite true; he looked thinner, and the shadows on his face were deeper. He had aged, she realized.

"Yes?" Snape prompted flatly.

"I'm curious why you were at Hell's Chateau, for starters."

"That, Miss Weasley, is my own business," he said coldly. "But rest assured. I am not dealing that abominable half-Muggle substance the Ministry seems so worried about."

"I didn't think you were, but good to know," said Ginny, smiling.

Snape drew his cloak around himself more tightly. "Are you planning to interrogate me, Miss Weasley? Exercising your Auror powers?"

"Professor, we're part of the old crowd," Ginny said. "I'm still making excuses for Mundungus, although Hermione and I sometimes wonder if it wouldn'tbe better if they just throw him in a cell for a few months."

"Hmm," said Snape. Coming from him, it was reassuring, thought Ginny, although his face showed nothing at all. "I've heard a few interesting things about the current state of the old crowd. It seems as though your brother is, shall we say, very involved."

"Oh, that," Ginny said darkly. "Fred's Order of the Phoenix." She shook her head. "He should stick to running Hogwarts. I've told him it's a bad idea, but he won't listen. He's made it into some sort of club. There're levels, and initiates, and you have to prove yourself before going to the next stage. I think it's stupid." She stopped, and, seeing Snape's coolly amused look, felt herself blush. Old habits die hard, she thought, especially with teachers. "Sorry, Professor. I was banging my cauldron there."

"What does your mother think of this?"

"She doesn't encourage him, but she's not stopping him either." She doesn't try stopping any of us anymore, Ginny thought, but held it in. An image flashed before her eyes, of her mother, sitting in her rocking chair and looking through photos of Ron, George, Charlie, her husband. Ginny pushed the thought out of her mind. Four years was still too short a time. "Anyway, I have to go back to the Ministry. Have a good day, professor. I hope I'll see you again soon."

Snape gave her a look that made it clear he begged to differ, but he said, politely, "And the same to you, Miss Weasley. Aura patrocinor tu."

Ginny started, but grinned. Trust Snape to know the traditional Auror farewell. "Aura patrocinor tu," she returned. Snape turned, drew his hood on, and disappeared into the street.

qp qp qp

"Granger wants to see you, Weasley."

Ginny looked up from her the stretch of parchment. The Head of Magical Law Enforcement Jack Demme—or "boss," as Tonks had convinced Ginny to call him—was standing in front of her desk, scanning the mess of parchment that covered it with a faint look of disapproval.

"Oh, Hermione?" said Ginny, feeling pleased. She stuck her quill in the inkpot and stood. No paperwork for the time being. Perhaps Cormac would deal with it, she thought, but decided that was distinctly impossible. "Did she way why?"

"Do you think Granger ever does?" Jack said, looking annoyed. Ginny grinned. "You might consider neatening up, Weasley."

"My side is clean, boss. Anyway, we made a crackle arrest."

"And that explains everything."

"Doesn't it?"

"Funny enough, it does," Jack said dryly. "Don't forget the Statutes of International Substance Control form. Tonks did, and all hell broke loose. Did Granger's bracelets work?"

"They did, very well," said Ginny, surprised. "Didn't Cormac tell you?"

"McLaggen has not come back yet."

"Oh. I s'pose he went to the dungeons first."

"Most likely. Don't keep Granger waiting."

Ginny stopped for some pepper-up coffee on the way there. She considered, without feeling the slightest bit guilty, the irony of the substance abuse inside the Ministry itself. Of course, this particular blend of Pepper-Up Potion and Muggle coffee was legal, but wasn't it in principle the same as crackle, a mix of a Euphoria Charm and cocaine?She drained her cup in the break room, which was empty except for a slightly nervous-looking, bespectacled young man sitting in a corner with a magazine in his lap. Ginny took a moment to wonder who he was, decided not to ask him if he was lost (he should figure that out by himself, she thought), and went to Hermione's office.

Ginny knocked and waited. She could hear voices inside—two, maybe three. "Come in," Hermione called.

Ginny pushed open the door and stopped short. "Fred! What're you doing here?"

"Ginny," said Fred, frowning with a smile on his lips and his arms held open as though expecting a hug, "is that the way to greet your favorite brother?" He had on a set of bright blue robes, which clashed horribly with the muted tastefulness of Hermione's office. He should stop trying to imitate Dumbledore, Ginny thought grimly.

"Sorry. You and Percy are pretty close, but I still choose Bill."

Hermione looked up from her desk. She hardly fits anymore, Ginny thought, taking in the distended stomach, which was bumping against the edge, even though the desk had been charmed to curve accommodatingly. "Hi, Ginny."

"Hi, Hermione." Ginny sat in a chair next to the one Fred was standing in front of, and leaned forward eagerly. "How's little Harry doing?"

"Kicking nonstop," Hermione said, smiling.

"Can I feel?"

"Of course," Hermione said. She pushed back slightly to give Ginny more room.

"Ooh! I can feel it! Oh, wow, he's got legs like a bludger." Ginny grinned; when Penelope had given birth to little Ron, Ginny had gotten to do the same, but that had been before she'd begun her Auror duties. In a strange way, spending so much time in the field made her appreciate Hermione's pregnancy even more. Sometimes, after a particularly difficult day, she would drop by and just bask in the presence of Hermione and her baby. It was like sitting in front of a waterfall, feeling a comforting spray fan her face. She wondered if other people felt it the way she did. Ginny looked up and noticed Fred watching her with a half-smile on his face.

She sat back. "So, just two weeks now?"

"Yes," said Hermione. "Honestly, I can't wait, if only to get Roger to stop nagging me to stay at home."

"You should hex him," Ginny said mischievously.

"Ginny, he can't defend himself."

"That's the whole point." Hermione's Muggle husband was more than a bit fussy, in Ginny's opinion. She was surprised that he had managed to adjust to everything that came with magic. But maybe most Muggles were like that, and her opinion had been distorted by Harry's relatives.

"I'll let you two hens catch up now," said Fred. He went to the fireplace. "Bye, Ginny, favorite sister of mine."

"Don't worry, you're in the top three," Ginny called as Fred disappeared into the flames.

"He is trying," said Hermione, absentmindedly stroking the sides of her belly.

"Yes, but I still can't believe what he's doing with the Order. He's made it into some sort of… circus. Or a cult, with him as the grand master. What did he want?"

Hermione paused. "Actually, it was for his Order to stick its fingers into this mission I'm going to tell you about."

"How did he know?" Ginny demanded irritably. Before Jack or me, she thought.

"The Minister probably told him," said Hermione. "I had to get permission from Rufus, of course. That was two days ago, which means that Fred has tea regularly with the Minister, or that Rufus reports to Fred."

"Neither is good," muttered Ginny. She wondered, for the umpteenth time, why she felt such animosity towards Fred's Order. She and Hermione had had many talks about this before. It wasn't because the Order really interfered with the Aurors, because they didn't, even if they sometimes made assertions that made Ginny wonder what exactly Fred's stance with the Aurors was. Neither could it have been because Fred was perverting the Order name, because he wasn't. Even with all the stupid elaborations, like the initiations and degrees of craft, he was still maintaining the principles that Dumbledore had founded it upon, and had expanded it and increased its fame. All that was missing was a Voldemort.

"He hasn't given you any trouble, has he?"

"You mean, with us Aurors? No. I don't know. And I know Fred's not going to do something terrible, like… try to be a second Voldemort. But it grates me somehow." Ginny shook her head. "He used to be so different, when George was still alive. Maybe—maybe that's why." She could feel the threat of tears at the back of her eyes, and saw Hermione's look of concern from the corner of her vision. She sniffed sharply. "Anyway. What's this mission you were going to tell me about?"

"Actually, someone else was going to tell you about it." She paused, then looked a bit sheepish. "I kicked him out when Fred came and went on about how he wanted to speak to me in secret. Silly, really, since Aaron—the guy—knows more about this secret than even I do."

Ginny straightened. "Is he thin, with glasses, looks a bit nervous? Wears a green button-down shirt?"

Hermione blinked. "Yes, did you see him on your way here?"

"Yeah, he's waiting in the break room."

"So that's where he went. I was afraid he'd wander off and get lost. You never know with magicists. Would you call him in, please?"

The man was in the same place as he had been when Ginny left the break room. She took a moment to observe him. Young, maybe a bit older than she. The shirt was fashionable, but made him look like he was conscious of it. His gaze flicked up for a moment but returned to the magazine.

Ginny cleared her throat. The man jerked; Ginny grinned. She liked scaring men. "Aaron?"

He nodded quickly.

"Dr. Granger wants to see you."

He jumped to his feet. "So she's done with her meeting with the fellow from Hogwarts? I was wondering when they'd finish. You know," he went on thoughtfully before Ginny had a chance to answer, "you look a lot like him…"

"We're both redheads?" said Ginny. For such a quiet guy, he sure could talk fast, she thought. "He's my brother."

Aaron blanched, but Ginny couldn't be sure. She led him to Hermione's office and returned to her seat.

"Aaron? Sorry to just drop you like that. As it turns out, you would've been the best person for Professor Weasley to talk to. Ginny, this is Aaron Skonser. Aaron, this is Ginny Weasley."

Aaron blinked at Ginny through his glasses. "So the two of you are siblings."

"Yes, didn't I say?" Ginny said, feeling a tad annoyed.

"Aaron," Hermione said in a way that reminded Ginny of McGonagall on a good day, "would you mind giving Ginny some background on the Borealis Expedition? She's going to be one of the Aurors accompanying you"

"Oh! Neato," he said, and grinned. This time Ginny was slightly taken aback. Aaron had a smile as bright as Lockhart's, but with none of the self-aggrandizement. And who says 'neato?' she thought. "Where should I start, Dr. Granger?"

"Probably with the trolleriometer."

The what? Ginny thought.

Aaron was at the back of the room, rummaging through a big paper bag. 'Ithaca's Grace,' Ginny read across the front. 'Quality Books.' "Here we are," said Aaron, pulling out a tripod in one hand and a large, bronze basin in the other. He set up the tripod and gently placed the basin on top of it.

"This is a trolleriometer," he announced.

"Oh," said Ginny. As if that explains anything, she thought, watching him take out a jug and a small circular object. She realized it was a spirit level when he emptied the jug in the basin, set the object on the ledge, and began adjusting the tripod.

"So… what does it do, this trolleriometer?"

Hermione stirred, but Aaron interrupted. "I'll explain further, but basically, it works like a Muggle compass, only it follows magical lines, not magnetic ones. Now. One more thing." He reached into the bag again and emerged with a small glass case. Opening it, he took out what looked like a thin needle the width of a hair. Carefully, he set it afloat in the basin. "There we go," he said. He turned and looked a bit nervous again. "Maybe you could come a bit closer and take a look?"

Ginny approached the basin and peered into it. The needle was floating in a pool of slightly amber liquid. Looks pretty, she thought absently. "Yeah. So?"

Aaron fidgeted. "Seeing as you work in Magical Law Enforcement, I'm sure you're familiar with magical detection tools, such as the skotadiometer, or the Curse-O-Meter?"

"Yeah, the Screamer."

Aaron smiled again, a quick blazing grin. "Oh, is that what you lot call it?"

"Take it with you down Knockturn Alley, and see if you can think of a better name."

"Oh, but can't you adjust the sensitivity?" Aaron said, frowning. "It's supposed to have a wide-ranged, continuous gradient—"

"We don't use it during the rounds so much as post facto," Ginny interrupted.

"Oh. I s'pose that makes sense." He turned his attention to the basin—or trolleriometer, Ginny thought—and continued. "Back when we were working on the skotadiometer, we were also working in parallel on a device that, instead of detecting the presence of dark magic, could direct you in the direction of it."

"Oh," said Ginny, thinking. "That would've been useful. Very useful, in fact."

"Yes," said Aaron, looking slightly embarrassed, "but we couldn't get it to work. Whenever we got it down to an acceptable sensitivity, the darn thing kept pointing north."

"North—like a Muggle compass?"

"Yeah, that's what Dr. Granger pointed out," Aaron said, darting a glance at Hermione. She had taken out a bag of raisins and was eating it together with a slab of Brie cheese. Ginny made a face, but Hermione smiled and patted her belly.

"But it didn't make sense, not a bit of it!" Aaron went on, looking more and more excited. "Could it be that there was a big clump of dark magic at the North Pole? So, well, anyway, one day I decided that it would be interesting to see how a similar apparatus would respond to magic besides dark magic."

"So Aaron very cleverly charmed the needle you see in the amber to respond to magic in general, not just dark magic," Hermione said. "It took him a year or two, but he succeeded very well."

Aaron turned brick red. "I just… observed a blueback beetle. They're sensitive to any sort of magic. Wasn't very hard. Anyway, after I did that, the results were the same—the trolleriometer pointed north. We thought, then, that it was probably the inherent magic of the earth doing things."

"That might've been the end of the story," said Hermione, who had moved onto pine nuts and peanut butter. "Fortunately, Aaron has a very keen sense of observation and a mind of logical inquiry."

"Well, if you think about it, it was the next step," Aaron protested. "The earth having some sort of innate magical field was a very plausible hypothesis. All you had to do to prove it was look at the magical dip."

"What's that?" Ginny interrupted.

"Oh, it's a borrowed term from Muggle science," said Aaron. "Basically, a magnetic compass points at an angle to the azimuth because the magnetic field of the earth isn't parallel to the earth's surface."

"What?" Ginny looked at Hermione for help.

"Wizards don't use magnets all that much, do they?" Hermione said. She pushed the peanut butter aside. "Have you seen this sort of diagram before?" She drew a circle in the corner of her parchment and took out her wand. "Vividus." Green and blue blossomed across the circle into an easily recognizable picture.

"That's earth," said Ginny.

"Yes. The reason why compasses point north is because there's a magnetic field through the earth itself." Hermione tapped the picture again, and lines sprouted from what Ginny recognized as the poles. They curved through space and met roughly at the plane of the equator. "These lines are magnetic fields. It's best if you consider the earth as an enormous magnet itself."

Ginny shook her head. "Looks like a Quidditch game play to me."

Aaron made a disbelieving sound, almost as though he were a bit offended. Ginny gave him a sharp glance. He shrank back. It was gratifying to receive such a response, Ginny thought with mild surprise and pleasure. She wondered if it was because she was an Auror, or if Fred was her brother. She hoped it was the former.

"In a nutshell, the compass—because it's also a magnet—follows these field lines. If you put two magnets together, they align in a specific way. This is the same principle, only, one of the magnets is the earth."

"And," Aaron added, when Hermione paused to let Ginny digest the information, "the reason for this is that the earth's outer core is made of liquid iron and experiences electric currents that fall into a pattern due to the Coriolis effect—"

"In a nutshell," Hermione cut in, "the earth is a big magnet."

"Right," said Ginny, before Aaron could open his mouth.

"But, the ends of the magnet, so to speak, aren't on the surface of the earth." Hermione tapped the picture again, and the greens and blues faded to translucency, like stained glass. The lines connecting the poles—magnetic fields, Ginny reminded herself—grew inwards until they nearly met at a point that Ginny guessed would be the center of the earth.

"As Aaron said, the part of the earth that actually creates these magnetic fields is in the middle of the earth, not the surface. That's why these lines are like this."

"Yes," Aaron said, looking eager to add more. He remained quiet, though, which Ginny felt grudgingly added points in his favor.

"With me so far, Ginny?"

"Think so," said Ginny.

"Right. So, as I might've mentioned earlier, magnets follow the strongest magnetic field lines around. That's why they always point north. However, if you put a magnet at the north magnetic pole, it would want to point inside the earth."

"Because the lines go into it," Ginny said, feeling understanding dawn with a flush of excitement.

"Yes," said Hermione, smiling. "Exactly. So if it could, the needle of the compass would point at an angle towards the pole that's inside the earth. That's called the magnetic dip."

"Right, I see," said Ginny. She waited for Hermione to go on, but Aaron jumped in instead.

"So basically, if the earth had an innate magical field analogous to the magnetic field, the trolleriometer would have a similar dip. Of course, it'd be different anyway because there isn't exactly a north and south pole with magic. Still, we'd expect the trolleriometer to have some sort of declination. But it doesn't. It points to the surface."

"Specifically," said Hermione, spreading peanut butter on a wheat cracker and sprinkling nuts on top, "it points to Svalbard. The surface of Svalbard."

Ginny frowned. "Svalbard?"

"An archipelago in the Arctic Ocean," Hermione explained. "It's under the Norwegian government."

"Wait," Ginny said, "so you're telling me that the trolleriometer, which is supposed to point at the biggest block of magic around, points to some island in the North Sea?"

"Actually, not the North Sea," said Aaron, "it's the Arctic Ocean, at the boundary of the Greenland, Barents and Norwegian Seas, but other than that—yes, precisely!" He was grinning madly. He's not bad looking in a cute, nerdy sort of way, Ginny noted after the brief moment of feeling disgusted.

"But why? And what kind of magic?"

"We know for certain magic in general and dark magic," Aaron replied.

"Ugh. So this Svalbard has so much dark magic on it that the trolleriometer ignores everything and points at it?"

Aaron paused. "Yeah. Basically."

"It isn't just dark magic," said Hermione. "Aaron charmed the trolleriometer to respond to magic in general, which includes three broad types: dark, light, and wild. Wild magic is generally much stronger than both dark and light magic, so it's reasonable to assume that wild magic is what the trolleriometer is responding to."

Ginny peered into the basin again. The needle shimmered alone in a lake of gold. One end, she noticed, seemed to dip slightly, although she could not be certain. The fluid was completely clear, and she could see nothing, not even a mote of dust, touching the surface. It reminded her, abruptly and surprising even herself, of what she thought the bubble around an unborn infant must be like.

"Right. So what's the mission?"

"I'm sending three of my magicists to Svalbard investigate," said Hermione. "Aaron is one of them." Aaron nodded at Hermione's side, the nervous look coming back. "They'll need Ministry escorts."

Ginny nodded, understanding. "Me." Hermione dipped her head. Ginny smiled. "Anyone else? Besides Cormac, that is."

"Just you two. Honestly, I don't think you'll meet much trouble on this trip, although whatever it is at Svalbard does sound intimidating. It's probably a tremendous reservoir of magical energy, like the auroras, although I'm surprised there hasn't been record of it in the past."

"The Tethyan Trench wasn't noticed until the late nineteen hundreds," Aaron put in, "even though it was a major outlet of telluric currents."

"That's because nobody could find the opening for centuries," Hermione replied in a somewhat long-suffering voice. She and Ginny exchanged a glance, and Ginny rolled her eyes with a smile. "That's all, I think," said Hermione. She hoisted herself out of her chair. "I'll finalize things with Rufus, and I'll ask Jack Demme if I could borrow you and Cormac."

They left the office, and Hermione followed them to the break room, where she poured herself some water. No hybrid substances during pregnancy, Ginny remembered. She settled into one of the comfortable chairs that reminded her vaguely of Gryffindor, if only they were red instead of green. The evening's light fell through the window and across the coffee table. Ginny wondered when the Ministry would put up a curtain; without it, the whole place had a feeling of being unfinished, despite most of the work having been completed two years ago. It had been a necessary relocation, after Voldemort blew up the original Auror headquarters.

"Oh—Hermione, you won't believe who I saw today," she said.

Hermione reached into her robe pocket and took out a Muggle sweet wrapped in some shiny material. "Who?"

"Professor Snape!"

Hermione stopped with a chocolate bar inches from her mouth. "Severus? Really! Where?"

"Um, outside of a… den."

"A den? You mean—where people do crackle and pot?"

"Yeah, but he told me he wasn't doing crackle."

Hermione shook her head. "There, of all places." She had a worried look on her face. "Did he look like he'd been using pot?"

"He looked older," Ginny said, a bit hesitantly.

Hermione was now chewing her lower lip, her gaze clouded with thought. "I haven't visited him in forever, not since we both left Hogwarts… I did visit him once in his actual home—this depressing place called Spinner's End—but that was—goodness, that was two years ago!" A look of stricken guilt had worked its way across Hermione's face.

"I'm sure Professor Snape can take care of himself," Ginny said, genuinely surprised by how worried Hermione seemed. "I mean, he always seemed to like being left alone…"

Hermione shook her head and fell silent. "Roger's probably home now," she said, changing the subject completely. "He's probably waiting in front of the fireplace, in case I fall down after I Floo. Honestly, I told him that the Maternity Wards wouldn't let anything like that happen, but no, he insists on waiting." She grinned, but Ginny could only half return it. She felt intensely curious about her old professor now, but it was not something she could bring upIn the last days of the War, Hermione had entered that isolated echelon of older Order members, and now, even after they'd become fast friends, Ginny could feel its remnants.

"I've paperwork from a crackle arrest to finish," Ginny said, standing up. "I wish Cormac would do some more of that. He seems to think it's a secretary's job, and therefore, Ginny's job."

Hermione's lips twitched, but her eyes were hard. "Do you want me to talk to Jack?"

"No," Ginny said hurriedly. "I'll just talk to Francine."

Hermione laughed. "Very good. I'll see you later then. Oh, and read up on Svalbard if you have time. It's fascinating—apparently, all the Muggles bear firearms, to ward off the bugbears, which were enchanted in the seventeen hundreds to look like polar bears."

"Sounds fun," Ginny said dryly. Hermione had pushed herself out of her chair and was now ambling down the dark hallway to her office. Ginny sat alone for a while, thinking of everything and nothing in particular, mostly debating whether she should have another cup of pepper-up coffee, before she heaved herself onto her feet, ready to return to the reliable chore of paperwork.