Sirius Black has all the traits of a good Slytherin son. He’s cunning, discreet, cautious. He’s the heir to the Black Lordship; son of Orion and Walburga Black and he knows that his home life… isn’t the best.
He also knows how to navigate around that.
Be everything they want you to be, because if you are mostly obedient, the little rebellions will go less punished. Have courage, of course—without it; without the belief that he is better than this, he would have nothing to make him deflect their ire from his brother. Nothing to carry him through these years, through the time before Hogwarts and the time during, and nothing to carry him into the years after.
Sometimes, he envies his cousin and her more blatant rebellion. He envies her for her more lenient parents—even as his mother, unable to disinherit, strikes her from the tree—and he envies her for her bravery and the ability she has to stand up for what she believes in.
Sirius shuts his mouth, hides his views and does all he can to protect himself and his brother. This is why the hat put him in Slytherin.
(In another life, perhaps he was more like Andromeda. Perhaps he rebelled, lived his life bright and loud and brave and Gryffindor. But in this life, Sirius Black decided that surviving was more important to him than living , and he adjusted his actions accordingly.)
On the train in his first year, he met James Potter. James was bright; a star as bright as Sirius’s namesake, and he laughed with his friends and welcomed Sirius with open arms. But then—
“Sirius,” Narcissa says, standing in the doorway. “We’ve been looking for you. Come sit with your family.” Narcissa is kind—kinder than Bellatrix, at least—but she follows their family rules, and she will most certainly tell his mother if he refuses to go.
(She will most certainly tell his mother if he looks back when he does.)
So Sirius Black walks out of that compartment, his first time on the train to Hogwarts. He leaves and he does not look back, does not indicate in any way that he liked sitting with those people—blood traitors and mudbloods—and when James catches him in the hall before they are sorted, Sirius clamps his mouth shut and does not reply.
James writes him off as snooty, stuck-up, a typical pureblood from a Dark family and it hurts, but Sirius bears it and smirks like he doesn’t care. “Why should I care about the opinions of a blood traitor?” he asks his yearmates. Most of them laugh and agree, but Sirius notices one who doesn’t—Severus Snape, half-blood, raised with muggles.
It’s that fact that draws him in. He sits next to Snape at breakfast that morning and walks with him to their first class (Transfiguration).
Unfortunately, doing so catches the attention of someone else.
(It appears that James Potter really cannot handle rejection.)
Snape starts avoiding him, and, because of this, his Gryffindor friend—Lily Evans, muggleborn—starts avoiding him too. James and his friends—Remus Lupin, Peter Pettigrew, Kingsley Shacklebolt—hate him anyway and tell the rest of the Gryffindor’s that he’s a typical, stuck-up, prejudiced pureblood. Sirius can’t even hate it.
These rumours—for that is what they are, having no rooting in fact—will get back to his family; will get back to Narcissa and Bella and Andromeda. And maybe Andromeda will hate him for it, but Narcissa and Bella smile, one grim but proud and one all challenging teeth, and invite him to sit with them at lunch.
This is how Sirius Black is pulled up the Slytherin hierarchy until he sits at the top of his year.
His parents would be proud.
Sirius ignores the jinxes sent his way by people he’d wanted to befriend, once; ignores the taunts from those in his year group and above; obliges those in his house who wish to use him to curry favour with his family. He reads the letters from his brother, replies to the letters from his mother, ignores the letters from his father and does all he can to be best in his year. Does all he can to please his mother and her unpredictable temper; his father and his cool expectations, because if he’s beaten out by the current top—Lily Evans, curse her—he will not like the consequences.
It is a stressful year; because of expectations, because of bullies, because he does not know what is happening at home; but he makes it.
He makes it to Yule—Lily Evans is still the top of the year when he gets home and his mother smiles that one specific smile of hers and Sirius bites his lip and tries not to scream when she turns her wand on him—and he makes it back to Hogwarts after the holidays.
He makes it to Easter—“that is a muggle holiday,” his mother screeches, “and we will not be associated with such filth ”—and he makes it back to Hogwarts afterwards.
He makes it to summer and he’s not the top of his year, but he’s second. It’s not enough.
(Regulus shrinks back into the shadows in the doorway and Sirius bites straight through his tongue so that his brother doesn’t have to listen to his screams.)
“It’s only one more year,” Sirius says, quiet. He’s crouched down by his suitcase, Regulus standing over him. Their parents, Sirius hopes, will not hear. “One more year, and you can come with me.”
“I don’t like being home alone,” Regulus whispers. It pulls at Sirius’s heart, but there’s nothing he can do, so he stands up and, grabbing his suitcase, gets on the train. It’s a callous move, perhaps, but.
There’s nothing he can do.
He doesn’t look back. Instead, he leaves his bag for the coachman and sets off down the train to his cousin’s usual compartment. When he reaches it, he fits in seamlessly, oozing charm and carefully masking how the jolt of the train when it starts moving is mirrored by a jolt in his heart.
This year, Slughorn determines Sirius old enough for an invitation to his ‘Slug Club’. Sirius graciously accepts, smiles in that way that makes every adult either swoon or believe in him unconditionally and promises he’ll be there.
“You don’t have to bring a date, of course,” Slughorn says, “you’re twelve! Some of the older years like to, though.”
“Don’t worry about me, Professor,” Sirius says. “I’ll just bring a friend. That way I have someone to talk to.”
“Of course, of course,” Slughorn says, “A brilliant plan, Mr. Black. I look forward to your presence!”
Sirius offers another blindingly bright smile, and goes to find Snape.
“It’s a chance to make connections,” he says. “I know you don’t like me, because I put you in Potter’s line of sight, but this… this could get you out of it.”
“It’s far more likely to put me more into it,” Snape says. He’s snide, sarcastic, not quite manipulative enough yet to make it. He needs connections and Sirius can offer them, but it’ll only work if Snape accepts his help.
“Think of it like an exchange,” Sirius says. “I introduce you to key players, help you navigate school politics. You help me with potions and charms.”
Snape eyes him warily. “Deal,” he says eventually, “but I’m not writing your essays for you.”
“I never asked you to.”
Sirius pushes his way up to first equal before Yule this year. Apparently, his acceptance into the Slug Club isn’t enough to offset the fact that the person tying with him is a ‘filthy mudblood’.
He grits his teeth and bears it.
On the train back to Hogwarts, he drags Snape with him into the upper-year carriage. Introduces him as a budding potions prodigy, then fits himself into the corner of the carriage. His hands shake—imperceptible, to most—and Narcissa’s eyes catch on him. She’s concerned, but she won’t say anything.
She’d never say anything.
Narcissa Black is a good, pureblood daughter. She will marry the man her parents chose (word on the street is that Cygnus has his eye on the Malfoy family; 6th year Slytherin Lucius Malfoy, to be specific) and she will not argue. She will bear him an heir, and she will live the rest of her life as a good pureblood housewife.
A life like that—a personality like that—leaves no room for saving a younger cousin that can’t get enough right to escape the Cruciatus.
Andromeda, though… Andromeda notices, and her lips tighten.
“Sirius, dear,” she says, “could you pass a message for me?”
Andromeda is the uncontested Queen of Slytherin, and she’s only a sixth year. Sirius nods, takes the note, and leaves.
(It’s addressed to him.)
He slips into the bathroom, takes the numbing potion she’d slipped into his pocket—he’s not entirely sure how she got one, but he’s never been one to look a gift horse in the mouth—and watches as his hands slowly, slowly stop shaking.
At this point, he’ll have curse damage. The human body is not meant to withstand the number of curses he must. Not in this short of a time.
(Sometimes, he wonders if his parents will kill him before the coming war does. Sometimes, he wonders if that death would be better or worse.)
Potter, who’d been ignoring him for the first term, picks up with the jinxes in the halls. Sirius begs a 5th-year shielding charm off Andromeda—in exchange for a favour, of course—and learns it with a single-minded determination.
Three days later, he teaches it to Snape. Snape teaches him a curse Sirius has never heard of before in return.
(Later, he learns that his new friend—or, the closest thing to it in Slytherin, Sirius supposes—has been dabbling in spell creation. It’s a bit young, being 12 years old, and Sirius would be concerned, but—
It’s not like he could say anything to stop him. It’s just a variation on the tripping jinx, anyway.)
The next time Potter comes after him, Sirius throws the shield up and trips Lupin into Pettigrew. They go down in a flailing bundle of limbs and Snape sniggers quietly from beside him. Sirius is suddenly struck by the need to make him laugh more.
“Try to be more dignified, won’t you?” Sirius drawls. “It’s unbecoming of a wizard, to not look where you’re going.”
Potter splutters, says, “You—”
But by the time he gets anything resembling words out, Sirius is already walking away.
He finishes the year coming first equal with Lily Evans. His parents are, of course, less than impressed. Sirius ignores his shaking hands and the weakness in his legs and goes to find Regulus, to congratulate him on turning 11 the day prior to his return. Regulus smiles, laughs at his gift and kindly doesn’t comment on how Sirius doesn’t make it to dinner. Instead, he brings a slice of cake upstairs.
“You get to come with me this time,” Sirius says, fork halfway through the slice.
“And I won’t have Lily Evans to compete against,” Regulus says with a shaky grin.
“You’ll do great,” Sirius agrees. He doesn’t tell Regulus that he’s scared to death of what their parents will do to him if Regulus doesn’t do well. Because they will do it to him—he would stop them if they tried to hurt Regulus, and hurting Sirius and making Regulus watch would be a better punishment anyway.
He’s not entirely sure he’ll make it to his fourth year.
He brings Regulus with him when he goes to find Snape—who will, no doubt, be sitting with Evans. When he does find them, he’s hardly surprised by the brilliantly purple black eye his friend is sporting.
“Here,” he says, brusque, tossing Snape a bruise cream he’d made up in the basement to help with his hip, “It’ll help with the bruising.”
Snape looks suspicious, but nods his thanks. “Who’s this?” he asks, inclining his head towards Regulus.
“My brother, Regulus Black,” Sirius says, throwing himself down on the seat opposite Lily. “Regulus, meet Severus Snape and Lily Evans.”
“Nice to meet you, Regulus,” Lily says, holding out a hand for his brother to take.
“I’ve heard a lot about you,” Regulus says diplomatically, instead of replying. He doesn’t take Lily’s hand. She frowns, glancing at Snape.
“Forgive him,” Sirius shrugs, “my family isn’t… entirely happy that someone of your, well, breeding, is doing better than me in school.”
Snape’s eyes focus on Sirius at that—a move so small it’s almost unnoticeable. Almost.
It’s a move telling enough paired with that bruise over his eye. Sirius offers a sardonic smile. “It would seem we are more alike than you’d think, Snape.”
“So it would seem.”
Sirius knows Snape told Evans—he sees how she looks at him and Regulus; concerned and worried and cautious, like they’re made of glass—but no matter how much she is careful with her words and her actions around him, she never does worse in class. She keeps getting top marks, keeps fighting with him for the top spot in their year, and Sirius can’t help but feel grateful for that.
If she’d started purposefully scoring lower, it would be charity.
Sirius cannot stand charity, even if with it he wouldn’t be lying by the fireplace with his every nerve on fire.
Regulus, at least, is the top of his class. This is a consequence of his own failings.
The year goes the same as always: the ‘Marauders’, as they’ve started to call themselves, pull pranks and fuck with Slytherins. Narcissa smiles and flirts with Lucius, as she’s been asked. Sirius and Evans fight for the top spot and, in the end, neither truly succeed.
Sirius returns home to a family that looks at his successes and labels them failures. He goes back to stand before them and wait for them to make him beg, because they have never yet failed to do so.
(Regulus came home as the uncontested best wizard of his year, and Sirius tells him to go upstairs in a voice hoarse with fear. They both know what is to come. That knowledge doesn’t mean Regulus has to see it.)
Sirius’s fourth year comes and goes with nothing truly interesting happening. It’s the same as the last: stress and exhaustion and a constant, never-ending intellectual battle against Lily Evans.
(The only real entertaining thing is James Potter’s decision that Evans is the prettiest girl he’s ever seen. Sirius is in Slytherin and he’s still heard at least one of the Potter Heir’s poems about the exact green of Evan’s eyes. It’s pathetic, honestly; entirely unbecoming of a pureblood heir. Sirius carries himself better, and he’s hardly the example of what purebloods should be.)
Fifth year is the interesting one. Fifth year is when whispers start up in Slytherin house—whispers of a Dark Lord, all-powerful, who wishes to eradicate muggles and mudbloods all-together. Snape stands firm against them, with his frankly far too obvious love for Evans, but Sirius…
For Sirius, it is what’s expected of him. He is sent back to Hogwarts after Yule with one task: do the House of Black proud and join the Dark Lord.
It’s Rosier who he corners in the end, a seventh year who bragged in the common room that he was the first chosen for the Dark Lord’s inner circle.
“I heard,” Sirius murmurs, keeps his voice silky-soft and quiet, “that it was my cousin who was chosen before you. Bellatrix, recently married to Rodolphus. You know her, I’m sure?”
“Yes,” Rosier says, and he’s utterly pathetic. Sirius hasn’t even cursed him yet. “I know her.”
“And I’m sure you wouldn’t want that claim getting back to her, would you?” he continues.
“No,” Rosier says.
“Then introduce me to your Lord,” Sirius demands. “As soon as you can.”
Rosier comes for him only days later. “The Dark Lord would love to have the Heir Black on his side,” he says. “He has demanded you greet him this coming holidays, at your ancestral home.”
Sirius inclines his head. His mother will be pleased, at least.
When Sirius arrives home, the house is alive with flurries of movement. It’s more active than Sirius has ever seen it and he finds out why when his mother finally stops bustling about to talk to him.
“He’s coming tonight,” she says, eyes bright and mad and terrifying, “You will start your service tonight.”
It hurts. His mother watches with wide-eyed glee and the Dark Lord watches with a specific kind of cruelty, and it hurts. It doesn’t matter, though: Sirius will not scream. He spent the first fifteen years of his life screaming.
He will not spend another the same way.
During his sixth year, he learns about animagus transformations. He knew of them before, of course; but this is a far more practical knowledge than that of before. Transfiguration is looking up this year.
He resolves to learn it as soon as possible. Not only will it be an invaluable skill for the Dark Lord to have at his disposal—no one watches their tongues around animals, after all—it is something that will finally test his inherent Black-bourne skill of transfiguration.
He writes to his mother for the first time in a year, and she responds by sending him every book on the subject the Black Library has to offer. Looking over the parcel, Sirius feels his lips stretching into a wild grin, full of the Black Insanity.
It would seem that’s something other than the heirship he’s set to inherit.
Three days after Sirius turns into a dog for the first time, Regulus joins the cause. Sirius can’t help but regret that—he’d wanted to protect Regulus, after all, and here is his brother, fighting a war.
Sirius resolves to end it quickly. Quickly enough that Regulus will never truly be called on to fight. He’s only fourteen still, after all. It’s not like the Dark Lord will have any real use for him until he’s sixteen, at least.
Midway through Sirius’s seventh year and Regulus’s fifth, Regulus is pulled out of class.
He doesn’t return for three days.
When Sirius gets on his last train home from Hogwarts, he’s aware he’s going home to fight a war. He sits in a compartment with his yearmates, all grim-faced and sullen as opposed to the Gryffindor’s rowdy cheer from the next carriage down.
They’re seventeen and eighteen and they’ve been at Hogwarts for seven years, and now they’re going to war. They’re going out to fight and die for a cause. A noble cause, to hear his mother speak.
Sirius isn’t even sure he believes that.
Regulus and Kreacher both leave for a few days at one point, but Sirius isn’t home enough to notice. He’s always out there, always fighting. He’s one of the best fighters in their army—the Death Eaters, led by Lord Voldemort.
(Vol-de-mort. Flight from death. Sirius can’t help but find that just a tad cheesy.
He only makes the mistake of thinking like that around the Dark Lord once.)
When Kreacher returns to the London house clutching Regulus’ body, Sirius wonders if all of this was worth it. Wonders if his own survival was worth his brother’s life; wonders if being everything his family wanted was worth picking the side of a madman.
A madman who split his soul, because Sirius recognises the kind of dark that comes from the necklace Regulus clutches in his cold hand. He recognises the magic itself as that of his Lord and recognises the darkness for what it is: a Horcrux. A version of dark magic that became so twisted it became in itself inherently evil.
Sirius wants no part in a cause like this.
He gestures for Kreacher to put Regulus down and step behind him; to leave the house itself and he stands in the doorway and looks at this place that was once his home.
“ Fiendfyre,” he says, and man and house-elf watch number Twelve Grimmauld Place go up in violent, uncontrollable flame.
“Professor Dumbledore,” Sirius says. He’s standing in the headmaster’s office, in front of the headmaster’s desk, with the mark of the headmaster’s current greatest enemy standing out stark and black on his pale forearm. It’s a wonder he isn’t dead yet. “During the end of year speech my final year here,” he says, “you said that Hogwarts would always have a place for any of us, if we needed it.”
“That I did,” Professor Dumbledore says mildly. He eyes the Dark Mark. Sirius doesn’t cover it.
“My brother died for the ambitions of a madman,” Sirius says. “I don’t want to do the same.”
Dumbledore looks up. His eyes are sharp, behind those stupid half-moon glasses.
“What do you have to offer?” he says, eventually. Sirius doesn’t blame him. They’re fighting a war, and in war, everyone develops a few Slytherin traits. It’s human nature.
“The Dark Lord made Horcruxes,” Sirius says. It’s a hand he revealed far too soon, if he’s honest, but it’s all he has at the moment.
Well, that and his illegal animagus status. Only one of those two secrets is likely to get him put in jail, though, and Sirius doesn’t want to reveal the one that will.
“He made Horcruxes,” he says again, “and four hours ago, I destroyed one.”
“Horcruxes,” Dumbledore says. “Plural.”
“Yes,” Sirius says.
There’s a pause, and for a moment, Sirius thinks that it wasn’t enough. Then—
“Welcome to Hogwarts, Professor Black,” Dumbledore says. “I trust you’ll pass your skills in defence on to the next generation.”
A year to the day later, the war ends. Peter Pettigrew betrayed James and Lily Potter, the news says. Kingsley Shacklebolt turned him in. Pettigrew told You-Know-Who where the Potters were living, and he went and killed them.
You-Know-Who tried to kill their child too, the whispers say. He tried to kill little Harry Potter, and he failed. He failed and the curse rebounded and he died.
The Dark Lord Voldemort, fallen to a mere child.
Sirius finds a grim sense of satisfaction in that. It must be embarrassing, being bested by a one-year-old.
(Later, he will learn that it was not Harry James Potter who bested You-Know-Who. It was Lily Evans, and Sirius will not be at all surprised.)
Ten years later, Sirius Black walks into the Defense Against the Dark Arts classroom and smiles at a group of waiting eleven-year-olds.
“In this class,” he says, “I will teach you how to defend yourselves. I will teach you everything that I learnt while fighting a war.”
And a little boy, sitting right in the front row; a little boy with green eyes and black hair and a lightning bolt scar; a little boy will lean forwards.