Dumbledore didn't have any other ideas—at least any that he was willing to share. When Harry had described the book with the yellow gem, the headmaster had seemed worried but not altogether surprised. He was very interested in the ghost of Tom Riddle, including his age and manner of death, but didn't see fit to explain why to Harry. He at least seemed as annoyed as Harry about how such a big clue had fallen into his lap only to be stolen right out.
For his part, Ron had a reasonably good explanation for how he'd seen a suspicious figure running down the hallway and given chase—but lost his target—Harry already missing by the time he got back. Myrtle stuck to her story about someone throwing the cursed object at her.
In the end, all the headmaster could really do was quietly look for both the book and the ghost of Tom Riddle. The student body was told that someone (which they could infer were a pair of redheaded twins) had put an embarrassing joke curse on a black book with a yellow gem in the cover, and no one was to touch it, but to call a teacher if they found it. Harry agreed that if they told everyone what it really did if you touched it, some of the students might consider it a challenge; or aspiring dark wizards might be very interested in owning the book. A general search of all books in the castle was infeasible: there were too many places to hide contraband, those with less dangerous but still banned possessions would freak out, and all the assailant really had to do was stash the book in the library or in a spare desk in an unused classroom and they'd never find it.
Dumbledore seemed certain that tracking and summoning magic would fail to affect the book.
Harry had quietly briefed most of his friends on what was really going on, for all that he was suddenly unsure who to trust. He didn't even know how long the mind control would have lasted. Could any or all of his allies currently be working for the sinister black tome, probably ultimately at the behest of the wraith of Lord Voldemort? Would they kill him in his sleep? Why hadn't his attacker killed him on the stairs, instead of just taking back the book? Did they need him alive and mind controlled for some reason? If they wanted him alive, then who had tried to hire the Dahvee to kill him?
It was enough to make a kid paranoid.
Most of the student body remained oblivious. There hadn't been any more attacks, and whoever was controlling the snake (which may or may not have been Tom Riddle) was laying low. Fandral's Valentine's contest was ultimately won by a Midgardborn Hufflepuff seventh-year that Harry didn't know, who enlisted basically her entire house to do a flashmob song and dance number to propose to her girlfriend. It was pretty impressive. Everyone but Harry seemed to be having a great spring.
At least Aunt Pepper (who was not pleased that there was now a mind-controlling book and the shade of his parents' murderer in the castle) had some good advice. She'd written to suggest that if the mind control was as simple as tapping people with the book, they could quickly just take over the castle. There had to be some limitation to it, so chances were that few, if any, of his friends were permanently mind controlled. She advised him to trust, but verify: assume anyone might be in the thrall of the book, but probably weren't. So as long as he could get two or three of his friends involved in any decisions, most or all of the decision-makers were probably okay.
Since he didn't know what he'd do without being able to confide in his friends, he was glad to have that sanity-check to keep him from turning into a shut-in, suspicious that everyone was out to get him. He was especially hopeful that Dean was in his right mind, because Harry's prime suspect was Ron, and he liked having another person in the room he could count on to keep him from getting killed or dragged off in his sleep.
But he was done with assuming that Dumbledore would just take care of it. Either the old man was incapable for some reason, or this was another deliberate test to see if Harry could handle it. Investigation by twelve-year-olds was back on the table.
Step one: Previous victim Myrtle. The ghost claimed that she couldn't remember how she died. Since she'd also claimed she couldn't remember anything happening when the book flew through her head, he had to assume she was compromised.
Step two: Hagrid. The big guy had conveniently gone on some kind of expedition and wasn't back yet to answer questions. Harry figured either Dumbledore was keeping the gamekeeper away from Harry, or, more charitably, had kept him out of the castle to remove suspicion if there was another attack (and maybe the pause in the attacks was because Tom was just holding off until Hagrid was back around to frame). They'd have to wait until he got back to question him.
Step three: Ghostbusting. From what research they could find, ghosts outside of Niflheim were barely more than holograms, pretty much impervious to anything but other ghosts. And when Harry and his crew asked around about whether the ghosts would be willing to try to dogpile the shade of Voldemort and his giant pet snake, at best they got empty promises.
They also wrote to the Masters for advice on ghosts, but their response wasn't helpful. Incorporeal apparitions weren't that common of a threat on Earth, and those that were often came from another dimension and had specific spells that could affect them based on their place of origin. The Masters didn't need to fight the draugr of Niflheim enough to have a default strategy. They figured that they might be essentially Astral projections, but Harry and his friends were a long way from being able to project Astrally and try to fight a ghost that way.
Step four: Training. In addition to doubling down on figuring out the general counterspell so he might have some chance of getting out of magical traps in the future, it was finally time to get training from the one person they knew who'd supposedly fought a Nidhogg serpent before.
"We need to actually learn to swordfight," Harry told Fandral, backed by Dean and Hermione, when they arrived to class early one day shortly after Valentine's.
"I'm certainly planning on–" Fandral started to explain.
"Today," Harry insisted, going over and grabbing a practice saber along with Dean and Hermione. "I'm not saying you can't tell us stories. Just, you know, teach us to fight while you do it."
"Of course, of course, I'd always intended to. This whole thing honestly reminds me of the time–"
Harry loudly clanged his saber against Dean's and asked, "Like this? How do I stand?"
As the rest of the class filed in and saw that there was actual sword practice going on, they happily went and grabbed their own weapons and Fandral basically had no choice but to teach the class. Every time he started to go off on a tangent, Harry or Dean would ask him another question about swordfighting stances. It finally started to become a class rather than Warriors Three storytime.
By the end of Spring-Month (which was probably sometime in mid-March, though Harry always had to do the math on a piece of paper to figure it out for sure), there had still been no new attacks, sightings of spectral Tom Riddle, or leads on the book. But they were feeling reasonably confident about their swordfighting (for all that they couldn't really get in a lot of out-of-class practice because of Wood's punishing quidditch training plan for the upcoming match against Hufflepuff).
They at least got a break from training one Sunday afternoon for the long-awaited electives fair. Well, it was less of a fair and more packing all forty-or-so second-years into a large classroom with the teachers of the five electives to explain why the kids should choose them.
"Remember, you must choose at least two electives. More are possible, but not always advisable, for all that they will look good on your transcripts," Rector McGonagall explained. "Now, let me introduce Magistra Vector."
Harry and most of the rest of the study group paid rapt attention to the school's math teacher. They were some of the only ones—other than Ravenclaw—to care. The dark-haired witch that took the front of the room seemed to favor red robes, and had clearly ink-stained fingers and a couple of uncaught smudges on her face.
"Thank you, Minerva," she said. Harry wasn't able to judge her age, other than indefinably adult. On Earth, she could have been anywhere from 30 to 60, and obviously the range was larger on Vanaheim. She had a bit of an accent that was possibly Russian. "I'm Septima Vector. The class I teach is called Arithmancy. It incorporates a great deal of mathematics, so is, at base, of use to any of you that plan to be involved in your family's finances, or any kind of scientific field." Not that many native Vanir were going into the sciences. "In addition to the more practical maths applications, we go into the geometry of spell forms. This makes it a key undertaking if you ever hope to alter or create magical spells. Finally, there's a fair amount of focus on probability and various forms of predictive modeling that can be used to make forecasts."
Off in the corner, Trelawney loudly scoffed, "Forecasting."
"You'll get your chance, Sibyll," Vector told her, flatly. "But, yes, the predictions we make in arithmancy don't require any kind of innate divinatory talent. Simply an understanding of how to assign and total chances that an effect will happen. It's less dramatic than a prophecy, but potentially more useful in the day to day."
"Thank you, Septima," McGonagall said. "Students, please save any questions to the end, where you can ask them individually. Sibyll, would you like to go next? Seer Trelawney, everyone."
Trelawney stepped up to the front, looking even more oddly-put-together out of the matching background of her office. She looked like a goth who'd accidentally shown up at a tupperware party. "The future," she moaned theatrically, deepening her voice and waving her hand in a long arc of fluttering black sleeves. "Your fate is already written in the weave by Urðr, Verðandi, and Skuld. What will be, will be. Or perhaps not, if you can learn to see clearly. Even if your ultimate destination is decided, however, prophecy can help you navigate the terrain between the now and the then. Not everything is about you, and you can experience feast or famine along the way without changing your conclusion. Divination is the many arts of understanding the future, the past, and the present. Why is what is, what is? How can you make use of this information?"
Parvati and Lavender were bouncing in excitement, and Parvati couldn't help but ask, "Do we need the Sight to take your class?"
The teacher shrugged. "It helps, of course, dear girl. But it is notoriously difficult to test for divinatory talents. If you believe you should take my class, that may be the Sight, in its unsparked form, urging you to learn all you can to ignite it. Destiny is a pathway, and if you are intended to see further than others, you must first climb as high as you can upon the structures that have been built before you." She took a long, pregnant pause, and then noted, "Because we focus on reading tea leaves, the weaving of the skeins of Fate, a fair amount of haruspication, and the like, even for those without the Sight, my class will teach you a number of arts useful in maintaining your home."
"Well spoken, as always, Sibyll," McGonagall shuffled her off. "Usher Burbage, if you'd please?"
A somewhat-meek woman of the core Vanir stock but with her hair dyed a bright bottle blond took the front of the room. She was wearing a strange outfit that seemed to feature a pair of slacks that could have come from Earth under a long jacket that was similar to ones Fandral liked to wear, pinned and patched with several dozen medals, buttons, and medallions from what looked like a range of cultures. "I'm Charity Burbage. I teach Cultural Studies. We go deeper into the various localities and politics of Vanaheim, but also do deep dives into the cultures, politics, and technology of the other realms. I'm especially fascinated by Midgard, so I hope as many Midgardborn as possible will take my class and expand my knowledge of what's possible these days. I hear there have been many breakthroughs since I was last able to visit about thirty years ago! I'm always trying to expand my knowledge."
Thirty years was a lot of Earth history to miss. Burbage hurried back to her place before McGonagall could ask her to step back, and she said, "Let's have Preceptor Babbling."
The witch who moved up was younger than the other electives teachers, and seemed to have a bit of a Persian cast to her otherwise Vanir features, for all that her accent was pretty standard for the planet. "I'm Bathsheda Babbling, and I teach Runes. Its basic function is to translate various writing systems, and we do a fair amount of introduction to different languages throughout the Realms, primarily dead languages that were used with various ancient runic writing schemes. This will include a study of the types of runes used by dark magic practitioners, such as witches, if only so you can recognize and counter them. Since skill with a quill, brush, etching fluid, and chisel are key to the rendering of many runes, you can also consider my class to teach you the fine arts, and we provide a strong foundation for drawing, painting, metalworking, and sculpture as well as calligraphy. However, the ultimate goal of the class is to learn to enchant items, which is usually handled by scribing them with runes of power. So you have that to look forward to in later years."
Harry gave a nod to all of his friends. Most of them could see the utility of being able to make their own enchanted items. McGonagall waited for her to leave then announced, "And finally, Mister Kettleburn."
"Silvanus," the man announced. He had stomped up on at least one prosthetic leg, and had one prosthetic arm. His gray hair was unkempt and his visible skin was covered in old and new scars. He said, "Husbandry. I'm actually retiring after this year, but I expect the new professor will do much the same as I have. Hopefully get less injured in the process. Husbandry's a lot about managing your herds and flocks. A bit of hunting lore, so you can live off the forests and plains. We also prepare you to capture, tame, pen, and otherwise handle some of the more dangerous creatures of this and other Realms. That's where you've got to watch yourselves and your fingers. It's a lot of fun, though it may cost you an arm and a leg in the long run." He barked out a laugh at his own joke. "Seriously. Only take this class if you don't scare easily and have some common sense in your head." He waved his prosthetic arm as proof, then stomped back off.
"And that's the overviews," McGonagall said. "The professors will be available for you to question for the next little while, or you can ask me questions as well."
They walked around a bit to talk to the individual professors, Dean admitting, "I don't know if I'm going to do the math with you guys. Seems like you'd need a bigger brain that I've got. I guess I can do Runes with you, though, now that I know it's the closest thing we get to an art class."
"Just keep in mind that you're pretty far behind on the math they want even for liberal arts universities," Hermione cautioned him. "You might have to take arithmancy if you want to go to college."
"I'll figure it out when the time comes," Dean shrugged. "Let's see what Burbage has to say about Earth culture…"
The blond professor really was thirty years out of date. She hadn't heard of cell phones or the internet. "Maybe I'll just go with runes and arithmancy," Harry figured, after talking to her.
"Thirty years probably isn't that badly out of date for Asgard, at least," Dean figured.
"Is anyone taking husbandry and divination with me?" Ron asked. "I hear they're the easiest. Plus, useful to know more about fighting beasts."
"I might," Hermione said. To everyone's surprise that she'd take those instead of arithmancy and runes, she admitted, "I want to see if I can take all of them."
Harry said, "Didn't we already explain you couldn't time travel to take extra classes?"
Hermione shook her head and explained, "I've been thinking about it, and I bet I can convince them to let me show up to class only on test days and major lectures, and otherwise miss some classes to take others, as long as I keep up with the homework…"
Dean just shook his head, "Hermione. No. You have to sleep. And you definitely wouldn't have time to practice martial arts and wandless casting with that schedule."
Hermione harrumphed in the way that meant she didn't have a valid counter-argument, finally settling on, "Well it's not like we've been doing that much this year, with Harry always at quidditch practice."
"Yeah, I'm thinking of dropping that next year," Harry agreed. "Too much practice time for one game a season."
Ron seemed scandalized, "Mate! But you're a great seeker!"
Harry just shrugged, "And I like flying. Maybe I'll stay on as an alternate if I can come to fewer practices. But Wood's schedule is crazy. I have other stuff to learn. There's got to be someone decent coming up. Does Ginny fly?"
Lavender nodded while Ron shook his head, and Lavender giggled, "She's been sneaking brooms out of the family shed to practice since she was little, because their mum didn't think she ought to be flying."
Ron gasped at that. "She never told me…"
Hermione bit her lip. "Okay. Arithmancy, runes, and probably cultural studies. But I may change my mind on that last one. Is anyone other than Ron not taking runes with us?" she asked the study group.
Everyone gauged each others' interest, and they mostly allowed, "As long as we can all help each other with it." Lavender and Parvati were obviously taking divination as their second, as was Neville. Padma was taking divination as well, to have a class with her sister, but also planning on arithmancy and runes with Harry and Hermione.
Dean finally decided, "If Hermione's going to take cultural studies, maybe I'll take husbandry, just so we have someone taking it that can tell everyone else if anything interesting happens." Ron and Seamus barely came to the study groups unless they were researching monsters.
"Sounds like a plan!" Hermione smiled. "Let's sign up!"
On the way out, Hermione dragged Harry and Dean off to the library, while the rest of the group headed back to the dorm. "What are we studying?" Harry asked.
She led them to a shelf and withdrew a tome she'd obviously browsed before, and set it up at a secluded table. "I'm worried about Eoster-Month."
"Why do they even have Easter?" Dean asked. It had bugged him the previous year, too. "Isn't that a Christian holiday?"
"That's why I'm worried," Hermione explained, flipping the book to an illustration of a man being pierced with an arrow or dart. "Christianity actually got the name from the Norse religion. In some stories, Eostre was the goddess who raised Balder from Niflheim when he was killed by a holly dart. Well, that's the Earth story."
"Oh, wait, I know this!" Harry said, having done a bit of his own research after playing the Baldur's Gate video games and wanting to know the origin of the name. "Frigga was so worried about her kid dying she got everything in the world to promise it wouldn't hurt him, so he was basically invincible. Except Loki found out that she'd somehow missed the holly plant, made a dart out of it, and tricked another god into throwing it at him."
Hermione beamed that she hadn't had to recount that part of the story, and expounded, "Except I'm finding out that a lot of the Norse stories got things a little wrong. Probably because they thought Odin had been king of Asgard forever, so moved the gods around. According to this book, Balder was Odin's little brother. He died before Thor and Loki were even born. It seems like there was some other god that nobody talks about much that did a lot of the really dark stuff that Loki gets accused of in Norse tales, but he wound up with the blame."
Dean was trying to keep up, "So someone did kill Odin's little brother Balder with a holly dart? And this Easter goddess brought him back?"
Hermione nodded, "Eostre. She was one of the earliest Asgardian sorcerers. It's hard to tell from the histories whether Balder came back for long, and might have just been like the ghosts we have here. But it was a big magical accomplishment at the time." She suddenly went off on a tangent, "I'm actually a little interested in who this god was that did all the evil stuff Loki's accused of, because none of the newer books talk about them at all, and the older ones just say things like 'abides in Niflheim' and it's not clear whether they died or just got imprisoned there–"
"Hermione," Harry interrupted what was probably a very interesting digression to Hermione but didn't explain why she'd called them there, "what's wrong with Eostre-Month?"
"Right," she brought herself back to the point. "They obviously liked that enough to name the first month of spring after her, and she's still famous two-thousand years or more later. I'm finding notes that all of Niflheim celebrates it. Between that and the mystical significance of rebirth and spring, I'm worried that the Nidhogg serpent may be more dangerous next month." They still looked skeptical and she said, "I checked the records. The end of Eostre-Month was when Myrtle died."
Dean summed up, "So ghost Tom may just be waiting until he and the snake power up before starting the attacks again. And he might be strong enough then to actually kill somebody."
"Exactly," she agreed.
"I guess we just keep watching each others' backs like we have been," Harry frowned. "Wish you probably weren't right."
Unfortunately, it didn't take long before they found out she was.
The next Sunday, on the day before Eostre-Month started, the whole school was preparing to head down to the quidditch pitch to watch Gryffindor play Hufflepuff. Except McGonagall stopped them at the front door and announced, "Everyone! Everyone back to your dorms. I'm sorry, but the game is canceled while we investigate. There's been another attack."
"Did someone die?" Harry asked, having been near the front of the crowd.
She shook her head, "Prefects Weasley and Clearwater are in comas like the others. They didn't return from their rounds last night, and they were just discovered in the second floor classroom corridors."
"Percy!?" one of the twins shouted. The other added, "But he's fully Vanir!"
McGonagall scowled, raising her voice to make it clear to everyone, "It was likely always a fiction that only Midgardborn were in danger. Now, back to your dormitories! A professor will come get you to take you to lunch. Get moving!"
Harry overheard Draco complaining, "Canceling quidditch just because of a Weasley and a mudblood. I can't believe it. I'm going to write my father!"
With Vanaheim natives now actually threatened, Harry wondered whether the Malfoys and other influential parents might do something about the problem… and he worried that whatever they decided to do would be even worse than what the headmaster had tried.
