Title: Onyx and Silver
Pairing: Harry/Orion Black
Content Notes: Implied time travel, angst, violence, magically powerful Harry, present tense
Rating: R

One of the first things Arcturus Black, Orion's father, told him when he was a child was that he wasn't a leader. Orion can still call the conversation to mind, the flickering sounds of the fire and the heavy apple scent of the candles that his father burned for good luck and concentration.

"You'll need to find a powerful leader to attach yourself to, Orion," his father said, leaning forwards and frowning at Orion where he sat by the fire. "You can't coddle yourself or act as if you don't know what to do. But you don't have the magic to stand on your own or convince others to follow you. Find a leader who has that magic and whom you can serve proudly."

Orion nodded, and committed the words to memory.

Honestly, most of the time, he doesn't mind not being that powerful. Leaders get constant challenges to duels—like his father does, or like Riddle—and doubted and gossiped about. They can never rest because they'll need to prove themselves at a moment's notice. And while Riddle and his father do indeed have powerful magic, Orion has noticed that they seem constantly on the verge of magical exhaustion, too, because they have to constantly use it.

No, not for him. He'll be happy to act the part of a follower in exchange for protection, relaxation, and serving as the occasional second in a duel.

That, of course, is what he thinks before Harry Potter shows up.

The boy tried to go by "Harry Evans" at first, when he was abruptly Sorted into Slytherin and had to join their sixth year, but that pretense only lasted a day. That wild hair and the lines of his face mark him far too effectively as a Potter.

Of course, Charlus Potter, a fourth-year in Gryffindor, immediately and hotly denied that that this boy was any relation to him. That only cemented Orion's belief—and the beliefs of most of the Slytherins, from what he can tell—that of course they're related, and Harry is an illegitimate child of the Potters. Perhaps of Fleamont, Charlus's uncle.

It makes the Slytherins interested in him, and interested in testing him. Orion watches his peers drop all sorts of lures in front of Potter, hint at secrets, ask leading questions, and fire jinxes at him when he's not looking. Potter counters the jinxes, in fact constantly shielding against them, and ignores everything else.

Well, okay, not everything. When Riddle tries to talk to him, Potter looks ready to choke on his own hatred.

Orion tilts his head a little as he watches their interactions. He could buy that someone who's used to being on the rough side of his relatives' tongues for being illegitimate, and probably a half-blood, wouldn't buy into Riddle's charm. But the hatred is something else.

And so is Potter's magic. Orion performs a useful little charm when Harry isn't looking, and stares in disbelief at the silver light that floods out around Potter, an aura invisible to anyone but him.

Potter is…

The most powerful wizard Orion has ever met, from that glow. Or at least he has the potential to be. Riddle's power is deeper, darker, and his father's more controlled, but Potter has some wild strength in him that Orion has never seen before.

Orion has been content as Riddle's follower for the past few years. Riddle is nastier than he thinks his father was thinking of when he recommended that Orion to attach himself to a leader, but he doesn't usually attack his own followers. Sometimes Orion has to walk on edge around him because Riddle conceals his emotions and then lashes out at someone for not realizing he was angry, and of course Riddle is a bit of a sadist, and there was that time he insisted Orion take the fall for a prank and spend a week in detention for the sake of Riddle not cursing Orion's pillow to bite through his throat…

Wow, Orion thinks, and has a sudden moment of clarity. Is that really the kind of thing I should tolerate?

The more he thinks about it, the more he doesn't think it is. It's just that the only two choices he has for leaders are Dumbledore and Riddle, and Dumbledore would never accept him.

But now, there's a third.

"What do you want, Black?"

Potter's voice is weary. He doesn't look up from the Charms book in front of him, which he's furiously taking notes from. He always stays in the most isolated corner of the library, probably in an attempt to keep people from coming to search for him.

Orion pulls out the chair across from Potter and sits down. "I've noticed that you're pretty good at Defense," he says. "Better than Riddle. I could use some help."

"No one's better than Riddle," Potter snarls, tossing his head up.

This time, Orion looks at his face, instead of the wild black hair clustered all around Potter's face and neck, and feels as though someone has cracked open his stomach. He's never seen eyes like that, so fierce and wild and green as the Forbidden Forest in spring.

"What the hell are you staring at, Black?"

Potter swears all the time, too. It's unattractive, but at least Orion knows he can always be sure of what Potter's feeling.

Orion coughs and drops his Defense book on the table. It's a new one this year. Professor Merrythought seems to have decided that their old ones were "holding them back" when it came to NEWT studies, or so Orion heard her muttering when he eavesdropped on her one morning before class.

"Riddle's good at curses," he says. "You're better at countercurses. I know you are," he adds, when Potter opens his mouth, probably to deny it again. "I've seen you reversing them. You do it faster than Riddle casts them."

Potter frowns and shakes his head. "But I'm not as strong as Riddle."

Orion blinks. He suspected many things about Potter, from the illegitimacy to the fact that he would have no friends in Slytherin, but not ignorance of his own power. "Of course you are. I'd say that you're at least his equal."

For some reason, the light in Potter's eyes dims at the words. He sighs and rubs his forehead, where an old lightning bolt scar sometimes catches the light. "You don't need to lie to get me to help you, Black. I'll help you if you want. What part of Defense are you having trouble with?"

"Dueling, actually," Orion says, happy enough to put aside his observations and get to work. "How can you keep up the barrage of spells when you also have to identify what's coming at you and counter them at the same time? I always get caught up in analyzing the other spells and overthinking it."

Potter begins to explain, and although Orion doesn't know how much he'll be able to use of the explanation—he just doesn't have the speed Potter is talking about, or the ability to shut his analytical mind down—he enjoys watching the motions of Potter's hands as he explains, and the half-smile he has on his face when he forgets he's dealing with another Slytherin.

That's another strange thing about Potter. He claims that he didn't know much about Hogwarts before he "had to" come here, but he sure seems uncomfortable in Slytherin, and Orion sees him staring at the Gryffindors with an odd mixture of longing and jealousy.

Perhaps I can show him that at least one person doesn't despise him, Orion thinks, and asks careful, intelligent questions to start maneuvering Potter to where he wants him to be.

Potter spends a lot of time sneaking out of the common room. Orion has noticed it and not mentioned it up until this point, because honestly, it didn't seem to have a lot to do with him. And it's not as though Potter is the only Slytherin who gets restless at night or has a desire to sneak off to the kitchens for a snack.

He starts paying attention after he decides that he might want to follow Potter, though. And he manages to slip after Potter—who's using rather a lot of secret passages for someone who "doesn't know Hogwarts"—out to the Quidditch pitch one night, and watches him charm his way past the lock on the broom shed.

Potter brings out one of the newer Cleansweeps, and leaps onto it.

And then he flies.

It's all Orion can do to keep up his Disillusionment Charm as he gapes. He's never seen someone fly like that, not even Abraxas, who's great at it. Potter rolls and swoops and soars, coaxing speed out of the broom that Orion didn't know it was capable of. He does a perfect Wronski Feint, and then turns the broom so it points straight up into the sky and goes up fast enough to tear his glasses off.

Of course, that doesn't happen. He must have some sort of spell to keep them fastened to his face.

Yet another thing that doesn't fit with Potter's story of having been raised mostly in the Muggle world and only coming to Hogwarts because everyone who could take care of him had died or was incapable for vaguely-stated reasons.

Potter comes back to the ground at last and slides the broom back into the shed, locking the shed with one sweep of his wand. He begins to stride towards the school, still darting from obstacle to obstacle so that he can evade the notice of anyone looking out through the windows, but so radiant with joy that Orion thinks he could follow his fellow Slytherin by the light he sheds.

Orion thinks carefully about that as he creeps behind Potter back to the Slytherin common room, and the sixth-year boys' bedroom.

He keeps the thought in his mind as he reports to Riddle, who of course is awake when he gets back, that Potter simply went to the Quidditch pitch and flew. Riddle snarls with discontent and falls back into his bed, drawing the curtains sharply shut. It's driving Riddle mad (madder) that he can't figure out why Potter dislikes him, and he also can't charm him out of it.

Orion is starting to wonder if it's as simple as Potter not wanting to be collected as Riddle's follower the way the rest of them are.

That might mean Potter doesn't have any idea about his own potential as a leader, either. He might imagine that he can simply stand aside from the whole drama of leaders and followers, that he isn't of much interest to anyone except Riddle, who wants to figure him out, and the professors, who keep subtly testing him, not just with exams, to see if he can keep up with the rest of the sixth-years.

Orion lies awake for a long time, thinking about what it would be like to follow someone who's modest, and humble, and glows with joy when something simple goes right for him, and ignores Riddle as if he's not worth bothering with.

"I challenge you to a duel, Potter."

Ah. Orion puts his homework aside. He wondered how long Riddle would be content to let Potter go without a challenge. Oh, they've dueled in Professor Merrythought's classroom, but that's always too tame for Riddle, since with a professor watching he doesn't dare use anything too Dark or sadistic.

Potter looks up from his homework, spread out on a small table near the windows that look out into the lake. It's the farthest from the fire, and thus in the coldest spot in the room, which means no one else wants to use it. Potter never acts like he minds, but then, he seems to be pleased by the Slytherins treating him like an outcast.

Orion wishes he knew why. Then again, he thinks it has something to do with the way that Potter seems so ignorant of his own power and content to leave behind anyone who would want to help him or follow him—if that's really what he's doing.

At least he's stopped insisting that his name isn't really Potter. Even the professors call him that, now.

"No," Potter says, and goes back to his homework.

The whole common room feels frozen. Orion can feel his eyes widening. Riddle just stares, looking gormless for the first time since the night he was Sorted.

"What did you say?" Riddle finally snaps. Orion shudders a little at the sharp hisses around the edges of the words. Riddle sounds as if he's about a step away from dropping into Parseltongue.

Potter glances at him again, entirely unafraid. "I said no. Do you need someone to explain one-syllable words to you now, Riddle?"

Riddle snarls, and draws his wand.

People hurry to clear homework out of the way, and games of Exploding Snap, or chess, or gobstones. Potter sits stubbornly right where he's been, eyes getting colder and colder. Orion licks his lips. He can admit to himself, now, how those green eyes pierce his composure, and he can admit that he's wanked thinking about them.

Wanked thinking about how Potter might explain things to him the way he did when Orion sought him out for dueling help, and how he smiled the night that he was coming back from the Quidditch pitch…

Perhaps he should be worried about Potter now, or about his intense attraction to someone who's never spoken a kind word to him except when he got caught up in giving Orion homework help. But Orion isn't. He sits there, and watches as Riddle fires the first curse, a nasty Torqueo that spirals towards Potter like a snarling corkscrew.

Potter lifts a shield at literally the last moment, leaving the spell to bounce off and hit the edge of the table holding his homework, twisting the legs. Potter catches his homework before it can slide onto the floor and gives Riddle a lazy smile.

Orion is glad that his Transfiguration book and his loose robes are covering his lap.

"I'm sorry, you were looking to challenge me?" Potter asks.

He's perfect, Orion thinks helplessly, in the moment before Riddle starts flinging Darker and nastier curses than Orion has ever seen him use.

Potter surges to his feet, not always meeting the spells, twisting out of the way of most of them, lifting shields, but surviving. That's not something anyone else has ever done against Riddle in Orion's memory, either. He watches, nearly holding his breath, as Riddle destroys Potter's shield and he raises another, as Riddle tries the Entrail-Expelling Curse and Potter fires back with a Tripping Jinx low enough to make Riddle stumble for a moment—

And then Riddle pulls back and roars, "Crucio!"

Orion hears more than one gasp. Distantly, he joins in. He knows Riddle must be near the edge of madness to use an Unforgivable at all, let alone in school where someone might be scared enough to run for a teacher—

All of that is buried beneath his pounding fear for Potter. Powerful enough Cruciatus Curses, held for long enough, can drive people insane. Riddle is more than strong enough to do that.

Potter twists away from it, but he's not smiling now. In fact, his eyes are so narrow that Orion is surprised he can see as he calls out, "Expecto Patronum!"

Orion has never seen anything like the silver stag that gallops from Potter's wand, or how it charges Riddle. It should be insubstantial, since a Patronus is really just a kind of mobile shield, but it knocks Riddle over anyway, maybe with just the wind of magic that comes along with it. Riddle's wand goes flying from his hand to Potter's a second later, as Potter Disarms him.

Potter stands staring at all of them for a second, Riddle on the floor and the gaping people watching from the couches. Then he tosses Riddle's yew wand back in his direction as if it's covered with bubotuber pus, gathers up his homework, which is miraculously barely scattered, and makes for the sixth-year boys' bedroom.

No one tries to stop him.

"Black."

Orion looks up, his heart bounding hard enough to make his chest shake. Potter is seeking him out at breakfast. It's probably only because Orion is the one of his roommates who's tried to talk to him outside of class instead of following Riddle's stance of shunning him, but frankly, Orion doesn't care.

"Potter," he says, and lets some of his smile shine through.

Potter, sitting down, gives him a baffled look from the corner of his eye, but shakes his head a little and seems to get over it. "Whatever," he mutters, apparently to himself. "Why is everyone staring at me like I'm the second coming of—Merlin this morning?"

Orion butters a piece of toast and wonders idly what Potter was going to say before the hesitation. "Because you put Riddle on his back yesterday, Potter."

"Oh…"

A soft flush makes its way over Potter's cheeks. Orion swallows. For the first time, he can see the appeal of dragging someone into a broom cupboard the way the Hufflepuffs are always sighing about.

"Still strange," Potter says, and snatches up a scone for himself. He barely seems to eat most of the time. Orion has no idea why, but he does know that he'd like to make sure that Potter eats on a more regular basis in the future. Can't have his future leader passing out in the corridors from lack of nourishment. "You'd think they'd be angry at me. You lot like Riddle, don't you?"

Orion jolts. It's a nasty reminder that while he's separated himself from Riddle's other followers in his mind, Potter has no reason to see him as anything but one of the crowd.

Still, though, it's suddenly intolerable. Orion stands. "Come with me, Potter," he says.

Potter does, letting the scone fall to the table after just one bite. Orion makes a mental note to bring him by the kitchens later.

Orion takes Potter to an alcove that's more or less resistant to Eavesdropping Charms, due to some property of the castle's stones and the way the defensive spells pass through here. Then he turns around and smiles.

Potter takes a step back that will allow him to draw his wand easily.

"It's not a threat, Potter," Orion says softly. Shit, he should have known Potter might take it that way. "You proved that you're stronger than Riddle. And that you aren't afraid of him."

"But I am, though."

"Then you're bloody good at not showing it," Orion says, and lets his smile widen again. He's not sure he believes Potter, anyway; yes, he might be wary of Riddle, but he doesn't feel the soul-defining terror that Orion has for the past three years in Riddle's presence. "Trust me, Potter, most people are a lot more afraid than you."

"But I know you're Riddle's—followers. That means you should be angry at me."

Perfect. Orion doesn't know how Potter knows about the Knights of Walpurgis, or exactly what he thinks of them, but that doesn't matter. He bows his head a little. "I've been looking to break away from him for the last few months," he says, conveniently omitting that it's been since he got to know Potter. "He's unstable, and he demands too much of me. But I didn't see how I could with the rest of my yearmates and the years above and below committed to following him. And then you put him on his back."

Orion can't keep from saying that. Merlin, it's a memory he'll cherish forever. That and Riddle's gormless look when Potter resisted him.

"Is that safe for you, Black?" Potter asks softly. "The others might not feel the same way. They could endanger you."

Potter sounds concerned. Orion would have written it off as a ploy or a weakness a month ago. Now, he's sure that it's its own kind of strength.

"I know that you'll protect me," he says simply. It's designed to appeal to Potter's weirdly Gryffindorish nature, but it's also the truth.

It works, too. Potter's eyes soften, and he takes a step towards Orion.

"I can't promise that I'll always be on my toes, though," he whispers, as if confessing some shameful secret. "I was last night, but Riddle could curse me in the back any time. So it might still be best if you stuck with him and acted the part of his loyal follower, rather than risk your neck associating with me."

Orion blinks as a new plan makes its way into his head, one he didn't think of before. "In public."

"What?" Potter blinks back at him.

His eyes are so bright. Orion has to stop himself from licking his lips, which would probably unnerve Potter more. He doesn't seem to be used to people desiring him or acting as if they want him around. "In public, I'll act like that," he replies. "Like Riddle's loyal little follower. But I'll spy on him and them for you, and warn you if it looks like they're setting up some kind of trap."

Potter closes hie eyes and mumbles something that sounds like, "Snape," for a second. Orion's about to ask him who that is when Potter opens his eyes. "It's too dangerous. I can't let you."

"I choose to do this," Orion says, jutting his chin up. He banishes his father's words about how he has to be careful about choosing his leader to the back of his mind. Yes, of course he has to be. And this is correcting a choice that he really should have known was the wrong one the first time he saw Riddle go into a mindless rage because Abraxas didn't give him a bow of the proper depth. "Are you going to force me not to?"

"No." Potter frowns at him, his eyes brightening again with his emotions. Orion just hopes that they'll gain allies who want to shelter beneath Potter's power without wanting to fuck him as much as Orion does. "I just—" He shakes his head. "You really know nothing about me, Black. You don't know that I'm not just as unstable as Riddle."

"I know," Orion says, fully confident. Potter, for all that he has secrets, also wears honesty on the surface of his skin. He won't turn on Orion. If Orion can convince him that they can be loyal to each other without fears of betrayal, what a friend—what an ally—what a leader—

What a spouse he'll make.

And Orion acknowledges his choice in the back of his mind. Father once told him that he knew Mother was the one for him the first time he saw her. It's taken longer than that for Orion, but he still knows that he's made the right choice. It thrums through his body like hot water.

Potter gives a soft half-laugh, shaking his head. "All right. Fine, Black—"

"Orion." He catches Potter's startled glance, and nods. So far, no one in Slytherin has invited Potter to address them by their first names, but that's all right. Orion is correcting that oversight. "Please."

"Harry, then."

Harry's still balanced, ready to strike or run or lash out with his magic if something happens. Orion approves, frankly. He'll have to show Harry that Orion deserves his trust, and he'll have to stay by his side and defend him against all latecomers, show Harry how much they need each other.

"Harry," Orion says, and receives a smile from Harry that he could put to devastating use as a politician. Orion smiles back, and gestures Harry out of the alcove.

They walk towards the Great Hall a little distance from each other, Harry picking up easily on the pretense that Orion wants to establish, not hostile but not friendly in public, either. When they get back to the Great Hall, Orion walks over to join the rest of Riddle's group, and Harry peels off in the direction of Transfiguration, their first class this morning.

Orion is smiling as he settles next to Abraxas's side. Abraxas gives him a sidelong look. He probably saw Orion leave with Harry. Orion personally plans for the Malfoy to be his first recruit. Abraxas obeys Riddle as they all do, out of fear for his power, but he hasn't had the same degree of true devotion since Riddle held him under the Cruciatus last year.

"Where's Potter?" Riddle snarls, eyes darting around the table. This close, Orion can really make out how paranoid he is, the way he clutches his wand as if his hand is a claw. Orion hides his distaste by bowing his head and answering in a pretend-servile manner far easier to fake than it has been for weeks.

"Gone to class already, my lord."

Riddle sneers and turns away, Summoning a cup of pumpkin juice from in front of a second-year. It splashes. Orion catches Abraxas's eye, and knows their thoughts must be at least a little similar, both about how the cup is bobbling and showing less than perfect control, and about how Riddle is bullying someone four years younger than they are.

Abraxas leans a little nearer while Riddle is snarling at Lestrange. "Tell him I want to talk to him," he breathes.

Orion keeps his face bland as he nods and begins a conversation about Charms. He's thinking about how Harry's eyes and smile, his joy from riding his broom, pierce Orion's soul, about how good he looks with a Slytherin crest on his robes for all that he seems to resent it, what it will be like to serve a true lord.

Someone who can't leave other people in danger, someone who will risk himself to protect them—although not unreasonably or without backup, if Orion has anything to say about it.

Arcturus left out one vital characteristic of a true leader worthy of following from his talk, Orion thinks as he swallows the last of his toast and mops his face with a napkin. Yes, magical power matters, and being able to be proud of your service.

But you need someone who can treat you more than fairly, who can defend you because that's the fire that burns through his body.

Orion goes to Transfiguration, where he'll see Harry, and starts daydreaming idly of the bonding ring that he'll get Harry sometime in the future. Silver, almost certainly, as all the Black bonding rings are. Emerald for the stone, to match his eyes?

No, Orion thinks as he enters Dumbledore's classroom and Harry glances sidelong at him.

Onyx, brilliant and black onyx, for the darkness that they will both swim through. And redefine.

Orion sits down, and listens to Dumbledore's lecture with light in his heart.