Harry knows there's a smug grin on his face when he walks into the Great Hall with his friends and all of their jaws drop open seeing Sirius sitting at the head table, even Blaise's and Theo's. Hermione, Neville, and Ron are a ways ahead of him and his Housemates, but all three of them turn around to give him varyingly dirty looks for keeping the secret. Beside him, both Blaise and Theo turn and almost in unison hiss, "Did you know?"

"Of course," Harry says, laughing. He waves at Sirius across the hall, and Sirius, also laughing as he watches this interaction, waves back, then makes a remark to McGonagall, seated next to him, that makes her roll her eyes.

The Slytherins make their way in a drifting clump over to their table, and Harry ends up sitting next to Theo, who turns immediately after sitting to give him a stern look. "I can't believe you didn't warn us that Lord Black was going to be the Defence professor!"

"Oh," says Harry, putting on an innocent tone. "Was that something you would have wanted to know?"

"Yes!"

"Well then," Harry says. He snickers. "Maybe next time. Anyway, he's very excited. And he's a pretty good teacher, though sometimes you need to ask him to explain things twice. He's way better at practical demonstrations."

"Has he been teaching you Defence this summer?" Blaise asks.

Harry nods. "Politics too, obviously, but we've been doing a lot of… I guess you could say foundation stuff. Running in the mornings and learning how to draw a wand quickly. Things like that."

Theo and Blaise both look intently interested. "Could you teach us some of that?" Blaise asks.

"If Sirius doesn't," Harry says, nodding. "I think—well. Anyway, it's kind of fun."

Blaise nods, but Harry notices out of the corner of his eye that Theo is looking at him carefully. Theo meets his glance and then turns away, says to Blaise, "Why on earth would you want to run in the mornings?"

"It's good for you," Harry insists. "You'll feel better, and last longer in a duel, and it's supposed to be good for your magic, too."

"There you go," Blaise says, waving at Harry. "Maybe you should start waking up earlier, Theo."

"Ugh," Theo says. Both Blaise and Harry laugh, well-used by now to Theo's feelings about getting up in the morning. All through first year, he was consistently the last one out of bed and ready, though never late; on the other hand, Harry was usually the first one up, and sometimes had gotten a pillow tossed at him by his grumpy roommate if he failed to keep quiet while getting ready.

"Well, I'll try it," Blaise declares. "If you'd like a running partner, Harry."

"Sure," Harry says. "I think I'm sometimes going to run with Sirius, but he said he wasn't planning to run every day at Hogwarts, and I am. But you can still join us if you want."

Blaise nods. "It would be a pleasure to get to know Lord Black better."

"Professor Black, now," Harry says. "Though he'll probably try to make everyone call him Sirius."

Blaise shudders. "I'm not sure I can manage to be that informal. I would feel my mother flicking my ear every time I did it."

"Me, too," Theo says. "My father'd have my head for being that casual with a Lord of an Ancient and Noble House, especially Lord Black."

Harry just shakes his head. His friends are welcome to try to out-stubborn Sirius, but he's pretty sure they're going to fail.

Then a hush begins to travel across the hall, and all of them look up to see that Dumbledore has stood up from his seat and is looking out at all of the students. Everyone falls silent, attentive, and Dumbledore raises his hands in a gesture of welcome. At the other end of the Great Hall, the doors open to admit the small column of first years, who look just as small and terrified as Harry had felt this time last year. They troop up the isle between the Gryffindor and Ravenclaw tables, following McGonagall like ducklings, and she leaves them there to go up to the stool on the dais and stand behind the Sorting Hat on its stool.

As with last year, a rip opens in the front of the hat and its folds fall into something approximating a face, and it begins to sing.

"You can keep your deerstalkers

Your caps and bowlers bold

Because none of them are talkers

Like the Sorting Hat of old.

I may not be so shiny

I may not shrink and grow

But don't think my magic's tiny

For there are many things I know.

I can look inside your heads

See exactly where you fit

Where each of you will make your beds

What fate for you is writ.

Whether it be in Gryffindor,

Where dwell the blunt and brave,

Voices like the lion's roar

From justice, never stray.

Perhaps endure when times are tough

With friends loyal by your side,

The earnest steadfast Hufflepuff

May hard work be your guide.

Or if you prefer to learn from books

Fly swift to Ravenclaw

Not everything is as it looks

Seek truth, seek wisdom raw.

And those who seek just to survive

Nay—those who seek to win

In complex times like these do thrive

Those wily Slytherins.

Let them never say of me

That I can't see what's really there

Or that my words are less than free

I might be clothes, but facts I bare!"

Different from last year's, just a little. Harry chews on the Hat's words as the Sorting Ceremony begins, tiny first years being called up one by one. He listens with half an ear to who goes where while he mulls over differences in the Hat's song, wondering if it means anything. A few names catch his ear as ones Sirius or Remus had mentioned, and he pays attention to those. Luna Lovegood ("Good old Xeno," Sirius had sighed, shaking his head, "mad as the proverbial hatter, and his wife Aster too, really, though she was also a brilliant spell creator—some of her work saved my arse a few times in the war. You'll probably be meeting their daughter at Hogwarts sooner or later.") goes to Ravenclaw; Iuliana Urquart ("Procne Urquart, Heir to that House, is a few years older than us," Remus says, patiently listing names, "but her daughter, second-in-line as it were, is a year younger than you. The family is mostly Ravenclaws, some Hufflepuffs, so you're unlikely to be close with her, but do introduce yourself if you have the chance.") to Harry's surprise ends up in Slytherin. And then of course Ginny Weasley goes to Gryffindor, to raucous cheering from her brothers. A few seats down from Harry, Malfoy scoffs audibly at that, and Harry rolls his eyes.

Once the Sorting is over and the first years have all found seats, Dumbledore clears his throat at the front of the room. The chatter that had arisen settles as the Headmaster smiles at them all benignly, and once it's silent he speaks.

"Welcome back one and all to another year at Hogwarts," Dumbledore says, "and to those who are new, a simple welcome. I am sure you are all very hungry and so eager to get to the feast, but first, a few start-of-term notices.

"Firstly, I would like to welcome to our staff this year's Defence Against the Dark Arts instructor, Sirius Black." Sirius rises amid applause and makes a showy bow, then sits again, grinning. Once it's quiet, Dumbledore continues, "Professor Black has graciously agreed to replace the late Professor Quirrell, who suffered a tragic accident at the end of the last school term. He is unfortunately only able to be with us for a single year due to his commitments elsewhere, so I hope you all shall show him the best our school can be, which I hope is perhaps slightly less chaotic than what it was when he was a student here."

Harry laughs, then shakes his head at the curious looks from his roommates and promises in a whisper to tell them later. Dumbledore isn't quite finished yet. He repeats his warning from last year about the Forbidden Forest being out of bounds, and tells the returning students that the third floor corridor is once more accessible, and that the Defence Against the Dark Arts classroom has returned to its proper place. Harry makes a mental note to pretend not to know how to get to that corridor better than he knows how to avoid it, and listens as Dumbledore offers another bizarre selection of nonsense words (among them "quince") before waving a hand to begin the feast.

The feast itself passes in a bit of a haze, filled with laughter and small-talk. Theo and Millicent get involved in a conversation about pro Quidditch, and Harry leans over to listen, occasionally asking questions about what this or that statistic refers to. He's planning to try out for the team when tryouts happen in a few weeks, and he's done plenty of flying, but between everything else this summer he hadn't had much time to try to learn anything about the way the game was played by the pros. Fortunately, neither begrudge him his questions, and in fact seem pleased to be pulling him into their love of the game. So they talk about sports and eat roast beef and potatoes and fresh dinner rolls, and then for dessert Harry has a generous slice of treacle tart. Eventually, he has no more room in his stomach, even for the wondrous food at Hogwarts, and the Slytherins begin to rise from their table and head down to the dungeons. Harry waits for his friends, who get up around the same time that the new fifth year prefects begin ushering the first years up and out of the hall. They follow the small group down through the hallways of the dungeons, and Harry breathes the cool damp underground air and refamiliarizes himself with the route, its turns and landmarks, and finally the stretch of wall that hides their common room door. The prefects step forward and the girl, who Harry doesn't know, announces the password clearly, so that everyone can hear: "Moly."

Inside, the common room is just as Harry remembers, and he glances up at the hissed greeting of the snake portrait over the mantle with a smile, though he reminds himself not to reply. Sirius and Remus had said nothing else about Harry's ability to speak with snakes after that initial revelation with Kingsley and Amanda, but he remembers their suggestion to keep it hidden—and the warning of the reception he might receive if he did reveal the ability. So he keeps quiet and looks around, absorbing the familiar details. It's like coming home, really—he's loved his weeks at the Doghouse, but there's nowhere like Hogwarts. Even if he has to deal with Snape.

And indeed, unlike last year, Snape is already present in the common room and waiting for them. He's standing in front of the fireplace just below the snake portrait, and all the Slytherins who left the Great Hall before the first years and Harry and his friends are still gathered in the common room, as far as Harry can tell. No one has dispersed back to the dorms, and Harry wonders with a faint sense of foreboding what Snape is going to say.

Of course, he doesn't say anything at all until the last of the Slytherins have trickled in from dinner, and then he raises a hand to catch their attention. What little conversation had been going on in the room ends instantly, all of the students turning to look at their Head of House, and he nods to their gathering.

"For those who do not know me, I am Professor Severus Snape, your Potions Master and Head of House," he begins. "In previous years I have allowed the prefects to begin with their orientation for the first years and allowed the rest of you to stay or my address or go as it pleased you; not this year. First years, the prefects will teach you Slytherin House's expectations for your conduct when I am done, but for now, I ask all of you to listen very carefully to what I am about to say."

He looks out across the crowd, his gaze pausing here and there, making eye contact with certain students and then moving on, making sure that he has all of their attention—and perhaps conveying some special message. To Harry's surprise, he himself is one of those whose eyes Snape meets, and Harry looks back as evenly as he can, feeling snared already as he was last year. Snape lingers on him for only a moment, but in that moment, Harry feels a gentle touch in his mind; his eyes go wide with shock even as Snape looks away. Harry hasn't learned yet how to build shields and misdirects in his mind, a proper Occlumantic protection, but he had learned enough to know when someone was trying to get into his head, and Snape had definitely been in his head just then. Subtle, gentle, a very light touch—but there. Harry scrambles mentally for some explanation for what Snape might have been trying to do, but he has no answers; he needs to talk to Sirius.

And he needs to listen to whatever it is that Snape's going to say, in hope that it'll give him some clues. Fortunately, Snape takes another few seconds before he starts speaking again, enough time for Harry to gather his thoughts.

"We as Slytherins are held separate from the rest of the school," Snape says. "We are reviled as a body by the other Houses, and while it is certainly possible to build individual friendships, they always exist under the weight of the dislike that everyone outside our House holds for us, our values, and what we do. Namely, that we openly admit our ambition. Do not be fooled: everyone has things they want. But Slytherins see no need to disguise that fact, to call it intellectual curiosity or earnest hard work or bravery in the face of opposition. All of those things serve a goal, and all of them have goals.

"We do not shy away from the fact that there are things in this world that we want, that there are goals that we pursue, and that we do what it takes to satisfy our ambitions. The Hat calls us wily, or clever, or complicated—all of these are true, but a better term is resourceful. Our cleverness is not bland intelligence. It is the ability to recognize something for its usefulness, which is something you will acquire if you do not have it already; our ambition is the willingness, then, to use that ability, which can only be inborn, and that is what a Slytherin is.

"If you wish to be successful here at Hogwarts and in the wider world, you will become resourceful, clever, in order to serve your goals. However, you must also clarify for yourself what your goals are. Each one of us in this room is an individual, with their own thoughts, biases, and connections. Consider that as you move forward this year, and consider yourself: what do you want? What do you truly want from this life? Who do you want to be? For if you do not make something of yourself, the world will make you into something, and it may not be something that you like."

Snape takes a long, slow breath then, that on another person would be a sigh, but on him seems only like a punctuation mark.

"Whether you choose to be aware of it or not, things are changing all the time, both within the school and without. My advice to all of you this year is to pay attention. Do not let the details pass by under your nose, for if you aware, you can be ready, and if you are ready, you can choose how you respond when the moment comes. As well, understanding the currents will allow you to protect yourself, prevent yourself from being swept up in the undertow of someone else's actions. These are the first and most basic tools of a Slytherin: awareness, calculation, preparation. If you do not use them, you are not a Slytherin." He pauses, only for a moment, then says, "But you are all Slytherins."

In the breathless silence left by his speech, he nods, gestures to the fifth year prefects to take the floor, and then sweeps away, making his exit from the common room with only the faintest snap of his black cloak and the click of the door settling back into place behind him. Everyone stands, almost stunned, for another moment, and then one by one the Slytherins begin to filter away. The prefects begin their usual beginning-of-year lecture to the first years, and Harry slips away, headed for his dorm. His mind is spinning, or so it feels, and he knows it'll be days before he can process what Snape said—and what it might mean.

Harry wakes early the next morning, as is still his habit even after a leisurely end of summer, and finds to his surprise that Theo is already awake and dressed, sitting on his bed. Theo looks up when Harry clambers out of bed, and whispers, "Meet me in the common room?"

Harry nods and hurries through his morning routine, wondering what Theo might want to talk about that he's gone to such lengths to catch Harry alone. He so rarely does anything without Blaise, and yet has chosen to avoid Blaise very carefully, even to the point of rising hours before his usual preference.

As promised, Theo is waiting in the common room when Harry comes out, and gestures for him to follow. Theo leads him out into the cool hallways and deep into the dungeons, walking a meandering path that seems designed to get them both lost. After close to ten minutes of quiet walking, Harry keeping track of the twists and turns as best he can so that he can find his way back if Theo ditches him, Theo stops. They're in an old abandoned corridor, the corners liberally covered with cobwebs, and there are few doors lining the walls; no one would have any reason to come here.

"What's going on?" Harry asks, once Theo has turned to face him.

Theo takes a deep breath, then says, "I'm trusting you with something."

"Oh?"

"My father is a Death Eater."

Harry blinks. Theodore Nott Sr. had been on Sirius's list of suspected-but-never-confirmed Death Eaters who were parents of his classmates, so it's not a total surprise. "Why are you telling me that?"

"Because I think something bad is coming, and Snape's little speech last night confirmed what I already knew—I'm going to have to pick a side sooner rather than later," Theo says. "I don't want to join the Death Eaters, Harry. But I'm not spy material, which means I'm not useful, either. The Light isn't going to protect me, so I've got to protect myself."

"But why are you telling me?" Harry asks, bewildered. "Do you think I can protect you, Theo?"

"You can." Theo's tone is blunt. "You're Heir Black, Harry, and Lord Black is close with Dumbledore. If you ask him to shelter me, he will, right?"

"Of course," Harry says without hesitation. "Sirius would want to help you, if he could."

"Good." A little of the tension flows out of Theo; he sighs. "I don't know much, but I'll give you what I do know. Things are happening, and happening fast. My father's mostly been staying out of it so far—he was always more on the political side, from what I can tell, which is how he avoided getting caught. But he's been meeting with some of his shadier friends and when I've managed to snoop into his correspondence, I've seen letters in code. And he's been muttering a lot about the return of the old order."

Harry nods. "Okay." He wracks his brain for what he needs to know now, and then says, "Listen, you've got to be careful. I know what's going on, and we're going to try to stop things before they get really bad—Sirius has been doing research all summer—but if we fail, you're going to be in a lot of danger until we can get you out."

"I'm in danger now," Theo says with a humourless laugh. "I'm necessary to my father, because I'm my mum's only heir; I'm all that gives him access to the Wizengamot. But he hates me, and I hate him."

A number of pieces are clicking into place now, things Theo has said in the last year, the way he acts. The House of Nott has a matriarchal hereditary seat in the Wizengamot, which means that the Ladyship is currently empty and will remain so until Theo marries or has a daughter, and if his mum was the born Heir, that means that without guardianship of Theo, Theo's dad will have no blood claim at all on the House. So Theo's dad is stuck with them, but it's clear that their relationship is sour. Harry gets that.

"Alright," Harry says. "So then you already know to be careful. And you know that…" he hates it, but he has to be honest, "that I can't make you any promises, right? I'll try to protect you, but it might not be possible."

"You have things you value more," Theo says and shrugs. "I understand."

Harry steps forward and places his hand on Theo's shoulder. "You're my friend," he says fiercely, so much so that Theo looks taken aback. "You're valuable to me. But if what I think is going to happen happens, no one's going to be safe and… and bad things happen sometimes."

He thinks of his parents, lying in those hospital beds. The grief that had aged Remus and Sirius prematurely. The photo they'd shown him of the original resistance, those who'd fought Voldemort in the first war, who'd been their friends—most of them are dead now, including Neville's parents. Skilled people, strong people, good people, but that didn't stop death from taking them. So, while Harry means it when he says that he'll try to protect Theo, or get Sirius to protect him, he knows there's no way to be sure.

"I guess they do." Theo's voice is quiet. "Listen, I don't know anything for sure, but the way you're reacting… what do you think is coming, Harry?"

"Do you remember how the third-floor corridor was blocked off last year?" Harry says, and when Theo nods, he continues, "Well, the teachers were hiding the Philosopher's Stone in the school. But Voldemort isn't dead, and he stole it."

"What," Theo hisses. "What? Harry, that's—he's dead! Longbottom killed him!"

"He didn't," Harry says. "I don't know what happened, but Voldemort is definitely alive and he has the Stone, and we think he's going to use it to come back. We're going to try to stop him, but… I don't know."

"That's insane!"

"I know! I know. Just… listen, if your dad says anything about the Stone, or buys any weird ingredients, or anything, tell me, okay?" Harry says. He squeezes Theo's shoulder and then finally lets go. "Sirius is trying to figure out what they're going to do with the Stone, but… it's really obscure."

"No kidding," Theo says. "The Philosopher's Stone is basically a myth."

"It's too real," Harry replies bleakly. "And Voldemort has it. So we've got to try to… figure it out, I guess. Not much to be done until we know more, right?"

"Like Snape said," Theo says, and sighs. "If you're aware, you can be ready."

Harry nods. "Exactly. And we need to be ready if we're going to survive."

Their eyes meet, and Harry knows that the fear he sees on Theo's face is probably reflected on his own. This stuff, it all feels too big for them. It's times like this that Harry really feels like he's still just a kid, when the world is falling down around his ears. It's the world they have to live in though, and Harry's not ready to lie down and die just yet, so they're going to have to muddle through. So he holds out a hand, and Theo takes it, and they shake.

"You're a good friend," Theo says. "More than I'd ever really expected, Harry. Thank you."

"You too, Theo. Now come on, we'd better get back, or Blaise is going to ask questions."

Theo shrugs. "I think I'm going to tell him, too. I don't want him to be caught unawares, either. I wasn't sure if you knew anything, but that's why I told you."

"Not just because I can protect you?" Harry asks as they begin their walk back through the dungeons.

"Nah," Theo says. "I don't want you to get hurt either, Harry."

"Thanks, Theo."

The two of them return together to their dorm, where Blaise is just waking up. He gives them both a strange look for being up and about, but says nothing; Harry expects Theo will pull him aside later and fill him in. He hopes that it'll settle the last of the lingering discomfort between himself and Blaise from their brief conversation after the theft of the Stone last year. Or maybe it'll only make it worse, that Harry had known this long that Voldemort was alive and working to return, and hadn't told anyone until now. He decides not to dwell on it; he has other things to worry about.

Like the fact that Snape had tried to use Legilimency on him on the first night. To Harry's frustration, when they receive their schedules at breakfast that morning, he discovers that the second year Slytherins don't have Defence Against the Dark Arts until tomorrow, and he doesn't know where Sirius's office and quarters are; he'll have to wait. Worse, Sirius isn't at breakfast, so Harry can't even try to catch him at the meal. With the troubling start to the day, Harry spends most of the first day of classes distracted, though not so distracted that he doesn't register that the second year schedule is fairly sparse, even more so than the first year one—they have long gaps in their days, which the professors seem to take as an excuse to fill the time with piles of homework. Harry will be spending a lot of his second year at Hogwarts in the library, reading for essays. Ugh.

Still, it's nice to see some of his professors again, especially Professor Sprout, smiling at all of them in Herbology. Harry hasn't missed Binns at all, and he feels like he's spent all summer catching up on the magical history he should have been learning in school, but at least he can use the period to get ahead on his readings before Transfiguration in the afternoon. Tomorrow, they'll have Potions, Defence, and Charms; no Astronomy until next Tuesday. In truth, Harry's glad to be back to learning magic after a long summer trying to learn politics. It's not that spells are easy so much as it's something that he knows he can do, or learn to do eventually, and he wants to know magic and do magic—it's wonderful to be able to use his wand again now that he's back at school and he feels surer with it in his hand. He has no such confidence about his ability to navigate the magical world's murky social waters, and even less desire. He tries not the dwell on that, though, and to enjoy his first day back at Hogwarts, the start of classes, the whole atmosphere of the place. He's seen more of the magical world now but there's really nowhere like Hogwarts, with its ancient stones and drafty halls and students all over, practicing spells and paging through old books. Harry had rarely read anything fantastical growing up, such books being banned by the Dursleys, but once in a while he'd heard a story during class storytime or had something assigned that was about magic and dragons and elves and such, and Hogwarts was like a place from one of those stories, truly magical right down to its bones. It makes Harry feel lighter just to be back here, to be a student again and only have to worry about becoming a capable wizard. So he tries to spend the day thinking only about that, about being in school and being a kid, and decides that tomorrow he can talk to Sirius and deal with all of the problems that have already come up then.

He even manages it. He can tell that Theo talks to Blaise that evening, because they disappear for a while after dinner and when they come back Blaise is bloodless beneath his dark skin and he gives Harry an unreadable look, but neither of them say anything, they just leave Harry alone to lie on his bed and read and then meditate before he sleeps, practicing clearing his mind. He sleeps without dreaming, rises early and goes for his run, and then gets ready for his day. It'll be a complicated one, he thinks—Potions first thing in the morning, and maybe Snape will finally stop ignoring him completely, and then Defence with Sirius right after lunch, which he's looking forward to but… has its own complications; he wants desperately to have some time to just talk to Sirius, but knows he's not going to get it until the evening at the earliest.

The morning starts out okay. Potions is fine… almost. The Slytherins are paired with the Gryffindors for Potions again this year, which Harry still thinks is stupid, but at least it means he gets to sit with Hermione and while they work they chat quietly about how their first nights went. Apparently things in Gryffindor are as always; Harry decides not to tell her about his conversation with Theo until he's had a chance to discuss it with Sirius. Snape doesn't ignore Harry quite so completely as he had last year, calling on him once when he'd put his hand up to answer a question, and pausing to give his and Hermione's cauldrons a narrow look, but he doesn't say anything. And then, as Harry is packing up and preparing to make his escape to the library so that he can start the assigned essay on the uses of lemongrass in potions with long brewing times, Snape says, "Potter, remain behind."

A few of Harry's Housemates pause very briefly, their eyes darting between Harry and Snape, including Blaise and Theo… and Malfoy. But they leave without questioning. Hermione pauses as well, looking askance. Harry just shakes his head and waves her off, and she goes without argument, knowing by now that he's not going to let her get between him and Snape. He finishes packing his bag and then waits.

Once all of the other students are gone, Snape says, "I will be in my office for two hours after dinner this evening."

There's an implied demand, but Harry's not feeling particularly gracious. "Good to know, sir."

Snape narrows his eyes. "I will expect to see you, Potter."

"Not going to send me a demanding note over breakfast again, sir?"

"No." Snape continues to give him that narrow look for a moment, then lets out a hard breath. "You are going to make a problem of yourself, Potter. Go speak to your useless dogfather, then come speak to me. Do you understand?"

Harry really wants to tell him not to talk that way about Sirius, but knows that it's not going to earn him any favour, and Snape is being weirdly mellow right now. "Fine, sir," he says instead. "See you after dinner, then."

"Good. Dismissed."

Harry is already on his way out the door, his mind spinning.

He has a spare block and then lunch before Defence. He goes to the library as planned, meeting Millicent and Theo; Blaise has gone off somewhere, claiming that he'll do his Potions essay later. All of them know that 'later' means 'at the last possible moment', but of course they also know that no amount of cajoling will stop him. Normally Harry would prefer to study with Hermione, since she has an encyclopedia for a brain, but the Gryffindors have Herbology with the Ravenclaws right now. Harry is a bit distracted, wondering what Snape's up to, but his friends being there keeps him on track enough that he makes good progress into the foot of parchment that Snape wants. Then they go off to lunch together and chat about Quidditch, and then head back to the dorms to drop off their Potions supplies and grab their Defence textbooks.

The Defence classroom is, of course, different than it had been last year. The normal Defence classroom is just off the third floor corridor, which to Harry's relief is markedly less gloomy and cobweb-covered than it had been. How it had gotten that way so fast he's not sure; maybe it had been an illusion of some sort to discourage the curious, or maybe Hogwarts' spiders were just very industrious. Either way, the doorway they go through is fortunately not the one to the room where Fluffy had lived. Instead, the door opens to a large room with one wall covered in windows, and set up with long tables in two rows with an aisle down the middle rather than individual desks. At the far end of the room, there's a staircase leading up to a doorway which, Harry thinks, might be the professor's office. Around the room, Sirius has put up posters with images of the wand movements for common defensive spells, which Harry remembers Remus coming home with one day from a trip to Diagon Alley. There are a few people already there, and, like Potions, they have this class with the Gryffindors. The tables seat four, to Harry's pleasure, and his Gryffindor friends have already arrived and have saved an empty seat at their table, just on the aisle. When he approaches, they all greet him cheerily and wave him into it, and he grins at them all as he pulls out and arranges his supplies.

The rest of the class streams in quickly, and then everyone waits. The time for the class to start ticks by, and the moment it does, Harry gets suspicious. He's not the only one glancing around, but he thinks that not many of the others know what they're looking for.

Sirius is a better-trained wizard than Harry and very good with illusion spells, which means that it takes a few minutes of searching for Harry to catch what he thinks is the faint distortion caused by a Disillusionment Spell. He focuses, trying to arrow his mind past the magic, and a moment later finds himself able to see the faint outline of a person standing just beside the Professor's desk at the front of the room. Harry isn't sure what Sirius is planning, so it gives it another two minutes before he realizes that Sirius is going to wait for someone to do something. Probably, from the muttering, someone is going to get up and try to leave in a moment, but Harry thinks that'll be less interesting.

Instead of waiting for his classmates to finish getting fed up, Harry slips his hands below the desk and draws his wand from his pocket as subtly as he can. With a twist of his wrist and a whispered incantation—which draws the startled attention of Neville, sitting to his left—Harry looses a Tickling Hex toward Sirius's hidden form.

As expected, in the next moment a shield blooms at the front of the room, and the hex splashes off in a shower of light. Students shout in surprise, even as the casting of the shield reveals Sirius standing to the left of his desk, and Harry had expected. He's laughing, and drops his shield.

"Good, Mr. Potter! Five points to Slytherin," Sirius says, and winks. "Admittedly you have an advantage because you know me, but even so: it's not easy to see past anyone's Disillusionment, never mind that of a well-trained wix."

Everyone else is whispering to their tablemates, and Harry beams up at Sirius.

Sirius grins back, then turns his attention to the class at large. "So. What just happened? Anyone?"

Hands shoot up, including, predictably, Hermione's; Sirius points at her.

"You were Disillusioned," Hermione says, "like you just said, of course. Harry managed to spot you—somehow—and then cast a spell at you. To avoid it, you cast a shield, and it's impossible to maintain a Disillusionment while casting other magic or otherwise doing something to actively draw the attention of those who might be able to notice you."

"Correct," Sirius says. "Two points to Gryffindor, Miss Granger. Now, can anyone tell me why what just happened was important?"

There's a murmur of uncertainty in the classroom, and then, hesitant, Neville raises his hand.

"Mr. Longbottom?"

"Er," Neville says, then takes a deep breath. "Well, if you were an evil wix of some sort and planning to harm us, then we'd have been in the room with an enemy for…" he glances at the clock, "almost ten minutes without seeing you. You couldn't have cast a spell without us noticing, but it'd only take one spell, and if we didn't know where it was coming from or if you got close and cast at point blank range, there wouldn't be much to be done. …Right?"

Sirius nods. "Yes. Another two points to Gryffindor for that astute answer, Mr. Longbottom. You should answer more confidently—you're right and you know it. In any case, for the rest of you: that is the exact issue, and very much relevant to what you will be learning this year."

Sirius begins to pace slightly, back and forth in front of the desk, gesticulating as he talks. "Unless someone manages to break that bloody curse," he says, causing a few students to giggle nervously at the sound of a professor swearing, "you'll have a different instructor every year, and many won't leave good notes for one another. That means you may end up with large gaps in the spellwork you learn, or with things repeated. I hope to avoid that by teaching you fewer spells and more how to use the spells you do learn. Not that you won't be learning spells in this class! You will. I understand that Quirrell did little practical work with you last year, and I hope that by the end of the year you will have the basic spells necessary at least to survive a dangerous situation, even if it means causing a distraction and fleeing."

Sirius stops and looks around at all of them. "I have been told that another professor at Hogwarts told you once that there will be no foolish wand-waving in this class." True: Harry had showed Sirius his transcript of the speech Snape had made on the first day, both of them laughing about the Potions Master's melodrama. "There will be no foolish wand-waving in my class, either. But only because all of the wand waving you do will be carefully considered. If nothing else, I hope that you will come away from a year with me with the ability to think, to assess a situation or a threat, and to decide how to react. How to react in time, in a way that will save your life."

His grave tone has the entire class silent and watching carefully. Sirius has as much presence as Snape, but different. There's so much light in his eyes, in his bearing, and he's so clearly tidy and put-together but not formal, that when he does become solemn and serious the effect is twice as strong. There's a pause as Sirius lets his words sink in, and then he says, "Not that everything in this class will be serious—except your instructor, of course; I am always Sirius."

There's a laugh, and Sirius joins them, then says, "I only get to make that joke once without it getting old, I'm glad you liked it. In any case: we will certainly be playing in this class at times. I hope that you'll trust me when I say that everything I do with you will have a purpose. If you cannot at first discern it, think a little deeper—and if you can't figure it out, I will be available in my office after dinner on Tuesdays and Thursdays other than today, and over lunch on Friday, as well as by appointment if you need. Please bring me your questions, because while there's every chance I won't know the answers, I will at least try."

Some students nod; others are noting down Sirius's office hours. McGonagall and Flitwick keep set office hours as well; Snape does too, but only once a week, and no one ever goes because he's notoriously vicious about any question he considers stupid, which is all of them. Professor Sprout can be found in the greenhouses almost all the time anyway, and can be approached during or after any class for an appointment, and Binns… is Binns.

Sirius goes on in his lecture, giving them an overview of some of the things that they'll be doing and advising that everyone acquire a pair of shoes with good grip, because they'll sometimes be running around. Harry listens carefully, even though he knows some of it—Sirius had bounced some ideas off of him during the summer, trying to figure out what their class had learned from Quirrell and what all of them as a whole might find interesting and useful, and what other things Harry himself needed to learn that everyone would benefit from. Obviously some lessons, notably the Occlumency and Harry's determination to master wandless casting, would not be shared, but plenty would. Harry had promised to try to get some of his classmates running with him in the mornings, with the added lure of Padfoot on Fridays.

It's going to be a good year, Harry thinks as the class wraps up and Sirius assigns a bit of reading for the next class. A very good one, hopefully. At the end of the class Harry lingers, of his own volition this time, and once the others are gone Sirius comes over and gives Harry a big hug, which Harry returns.

"Good lecture, Sirius," Harry says cheerfully.

"Glad you liked it! Good work with the Disillusionment." Sirius ruffles Harry's hair, drawing a playful scowl, and then continues, "Come see me after dinner tonight, alright? We'll figure out a more regular time, now that I've got my teaching schedule sorted."

"Yeah," Harry says. "Sounds good. I've got a lot to tell you."

"Already?"

Harry nods, and Sirius's expression drops a little.

"Alright, pup," Sirius says, and bends to kiss Harry's forehead. "Good luck. See you in a few hours."

"Bye, Sirius." Harry resists the urge to hug Sirius again; he doesn't need to be held for comfort. Instead he steps back, waves, and darts out into the hallway to go find his friends. He's still got a few hours to relax before he's got to try to explain everything to Sirius… and deal with Snape.