This is a coda to Ragtag Heroes, not really intended to become a separate thing but my attempt to get into Sirius’s head. Excuse me while I upend my drabble bin over your heads. :D
Sirius’s little brother has always been just that—little. Regulus was a slight and slender child, and has grown into a lean and lithe man, a little too thin and rawboned from constant stress but still pretty in the way that their parents always despaired of. Sirius can admit, despite his hatred of her, that Walburga Black was an absolutely stunning woman, and Regulus takes after her very much in looks.
Not so much in personality, though, regardless of what Sirius thought as a child. Not after what he’s managed to accomplish.
Slumped in a dusty old armchair, Sirius watches his brother wander around Grimmauld Place’s library, touching covers, stroking long fingers over worn spines. This is Reggie’s element and always has been—Sirius was honestly astonished that he ended up in Slytherin rather than Ravenclaw, during the Sorting. Regulus as a child, in Sirius’s mind, was forever clutching a book, sometimes as big as himself, and wandering around with a dreamy, distant expression. He thinks of it with a bit of a pang, now, because at some point during his first year at Hogwarts that warm burst of fondness at the sight of his little brother, forever trying to please everyone, transformed into something sneering and derisive and passively loathing.
Regulus being sorted into Slytherin was the final straw, and Sirius, already immersed in being different from their parents and surrounded by Gryffindors who held the same beliefs, had turned his back on Regulus, not about to associate himself with a sniveling follower.
Never mind the fact that Regulus was eleven. Never mind that their parents had always leaned harder on Regulus, who was never nearly as willful. Never mind that Regulus adored Sirius since birth, as the only one who spent any amount of time with him outside of the house elves. Sirius had turned away, found a new brother in James who suited him so much better, and left without a backwards glance.
Their parents were never kind, even to the family favorite, and Sirius watches Regulus meander through the shelves with something like guilt roiling in his gut. Should have known, he thinks, and the vague, distant regret he’s felt since learning of his brother’s death is back in full force, because Sirius had run away from the family and left Regulus behind. It doesn’t matter that they were at odds at the time; Regulus was always a gentle soul, always tried to please their parents no matter what. Sirius could have easily taken him along to James’s, could have convinced him to abandon their parents’ ideals if only he’d remembered the sweet little boy Regulus had been, rather than looking at the distant, aloof Black prince he’d been forcibly molded into.
But he didn’t, hadn’t bothered, and something in Sirius is—
“Leo Prince,” Regulus says unexpectedly, making Sirius jump.
“What?” Sirius asks, blinking.
When he looks up, Regulus is giving him that nostalgic you’re-a-moron-Siri-and-must-I-lower-myself-to-your-level look. He’s seen it quite often—usually from the child Regulus used to be, excited about some obscure spell or ritual or potion, some little-known aspect of ancient magical theory that lost Sirius completely about twelve words into the explanation. Not that he’s an idiot, academically—Sirius has always been proud of his grades—but Regulus is something entirely different. Even their parents never quite knew what to do with him, beyond shipping him off to Voldemort in a gift-wrapped package.
“Yes, Reggie?” Sirius grins at his little brother, for the sole reason that the nickname drives him batty and nothing gets his ire up like pretending to be stupid. “What was that?”
Regulus rolls his eyes so hard Sirius wonders how he doesn’t strain something. “My name,” he explains, tone long-suffering, “for teaching at Hogwarts.”
Sirius turns it over in his head for a moment. “Leo?” he repeats dubiously, because outwardly Regulus is the perfect Slytherin, and whenever he’s not being Slytherin he gives a damned good impression of being a born Ravenclaw. Nothing leonine about him, really.
That gets him another roll of Regulus’s eyes, though it’s subtler this time. “The star Regulus is the brightest heavenly body in the constellation Leo,” he says, and his mouth quirks in a wry smile. “Also called ‘the Heart of the Lion’.”
Sirius snorts at that, wondering what twist of fate gave Regulus the one Black name that suited him exactly. ‘Heart of the Lion’ indeed. “And Prince?”
“From the literal meaning of my name.” Regulus turns back to his books again, plucking one off the shelf and adding it to the already sizeable pile he’ll be taking to Hogwarts with them. “’Little King’. It’s a name I’ve used before, in parts of the Continent. So if a particularly overprotective parent should try to trace my movements, there will be a trail. Leo Prince spent two years in Italy and then Eastern Europe, studying blood rituals from ancient times.”
Of course he did, Sirius thinks with a roll of his own eyes. He’s spent several weeks already with Hermione, and even she can’t hold a candle to his little brother. But rather than say anything—although it’s tempting, because Reggie being defensive over his rituals and spells is easily one of the more amusing things Sirius has ever encountered—he just asks, “And disguises? It’s more than likely that Peter told Voldemort about my Animagus form, and I hate to say it, Reggie, but you—”
“Yes, yes,” Regulus cuts him off, clearly annoyed. He’s always been easy for Sirius to rile. “We look very similar, I’m aware. Harry thought I was you, at first glance.”
Sirius blinks and fights a frown. Regulus is pretty, and Sirius has always considered himself—not without corroboration from other sources—to be handsome. Then he glances up, catches the tail end of Regulus’s wicked grin as the younger Black turns away, and huffs. “Oh, go on, rub it in,” he growls, chucking a cushion at his smirking brother. “At least I take after Father rather than dearest Mother in looks, pretty boy.”
That earns him a rude hand gesture and a scowl. “Anyway,” Regulus says forcefully. “I won’t use charms to change my appearance—they’re too easily detected and broken, even by the simplest of wards or spells. But…” He trails off, rummaging in a cupboard for a moment, and then, with a victorious sound, emerges holding a pair of glasses with delicate silver frames. He slips them onto his face, then pulls his hair from its loose tail and twists it into a messy braid falling over his shoulder.
They’re simple changes, but they’re able to highlight the differences between them. Sirius sits up straighter, taking in the way the glasses manage to entirely change Regulus’s face, and the hairstyle gives him a bookish, distracted, professorly air. With a change of clothes—good-quality robes, he thinks, maybe a little tattered, quiet colors, slightly too large—Regulus will be all but unrecognizable. Oh, there will be similarities, but there used to be a pureblood Prince family, and they intermarried with the Blacks enough to write off the resemblance as a result of typically tangled pureblood genealogy.
Regulus is giving Sirius the same look in return, but his is faintly distracted. “You, however,” he murmurs, “will need a charm or two, if only to keep from giving any of the more superstitious students a heart attack, looking like a Grim.” He trails off, muttering under his breath, his gaze absent, and Sirius realizes that this is his contemplative look. He’s no doubt running through every glamour charm he knows, cataloguing faults and weaknesses.
Such a Ravenclaw, really, Sirius thinks, and doesn’t even bother to fight the fond smile that rises. Good old Reggie, the walking encyclopedia of spells.
Then Regulus looks up at him and smiles that singularly angelic smile that means he’s about to show how he and Sirius really are related. He taps long fingers against his lips to hide the beginnings of a smirk, and murmurs, “Well, you’re the size of a bear, so there’s no way we’ll actually be able to pass you off as a normal dog, but…white, I think. Yes, white will do nicely. Maybe with a touch of tan?”
Sirius only has a moment to feel horrified before Regulus’s wand is out and moving.
“Well?” his little brother demands, sounding unnervingly like McGonagall. “Change already, we haven’t got all day.”
It’s going to be a very long year indeed.
It’s been a near age since Regulus last set foot on Hogwarts ground. He stands just outside the gates, staring up at the vast and imposing castle—strangely comforting, a home more than Grimmauld place could ever be, and he wonders if it’s like that for everyone. Perhaps only those from broken homes, if the Black family can count as such. Sirius, at least, had the Potters, but Regulus was always a distant, aloof child with few acquaintances and fewer friends. He had no one.
Unconsciously, his fingers curl into the thick fur of the beast standing at his side, higher than his waist and as big as a bear. White fur now, rather than black, but it’s still Sirius, still his brother brought back to him. Maybe everything isn’t entirely easy between them yet, but they’ve been strangers longer than they’ve been family, and they’re readjusting. Sirius whines softly and bumps against his hip, and Regulus musters up a smile for him.
“I’m fine, Siri,” he murmurs, although his fingers stay buried in pale fur. “Just…overwhelmed, a little.”
Normally he’d never admit to such a thing, but this is Hogwarts and he’s coming back and there’s absolutely nothing in the world he’s dreamed of more than destroying the Dark Lord with his brother at his side and the Light at this back. This is a step closer, the fifth out of seven, and then there’s only the snake left to find. Regulus has thrown out his net already; there are many people who owe him favors by now, with his knowledge base and skill set and Slytherin cunning, and Nagini will be found soon enough.
Just Ravenclaw’s artefact now, and then Harry. Their goal is so close, so achingly close that Regulus can almost taste it, and after sixteen unwavering years, he’s ready. Ready for a normal life, a death not at the hands of his former master, days not spent running from even the vaguest chance that Voldemort could discover him or his plans. It’s been too long.
With a huff of very un-canine impatience, Sirius shoves at him again and then heads up the road, strides sure and confident. Regulus only hesitates for a moment longer before hurrying to catch up with him, careful of his baggy robes. He hates them, if only for Sirius’s teasing at how he looks like a waifish scholar who thinks too much to eat. Not that Sirius is one to talk, really—he’s changed from looking like a Grim to looking like something out of Norse myth that’s about to devour the sun.
But Sirius is happy to be out of that dreary and rundown house, and Regulus can’t blame him. About the only good thing remaining there is Kreacher, and the elf is getting on in years. He’d been overjoyed that Regulus returned, but as much as Regulus missed him he hadn’t been able to bring himself to stay. He’d packed everything he needed in a day and headed out to Hogwarts and his new post, Sirius in tow. They’re quite a pair, really.
McGonagall meets them at the main doors, still regal and authoritative in a way Blacks can only dream of being, but she smiles faintly at Regulus. “Professor Prince,” she says. “How good to have you back. If you’ll follow me, I will show you to your chambers.”
This is happening, Regulus thinks suddenly, as his heart stutters and leaps forward into a gallop. This is real.
Professor, she called him, and that’s what he is now. No longer a nameless, fleeing face but a person, a figure of some standing, with a name and a past even if it isn’t his own.