Sirius had left. Regulus stood at the top of the stairs when his brother screamed at their mother about how he was never coming back and then walked out. He took a small backpack, the rest of his stuff had already been deposited at his friends’ over the years.
In the next years, Regulus would vow he hadn’t cared. But here, at the top of the stairs, he quieted his sobs and turned to walk away, tears streaming down his face. His brother, the only reason to hold on and keep his forearm unblemished for a little longer, was gone. Truly and forever.
There was one month left before his inevitable return to Hogwarts so he decided to make the best of it. He ate dinner with his mother every night and agreed to every demand she made. He went on three different outings with upper class pureblood women including his cousin Narcissa. The two did their best to pretend it was just a cousins’ day out. He told his mother he would prefer marrying a bit more removed, if only to strengthen political alliances. His mother approved.
After having been perfectly obedient the whole summer, his father decided he should receive the honor of meeting his soon-to-be master. So it came that he was introduced to Voldemort. The dining room was set for a dinner party, as if they were entertaining some prospect’s family. Regulus was told to wear formal dressing gowns.
“Ah, a pureblood prince indeed” the man with snakelike facial features whispered.
The noise shouldn’t have carried like it did, but everyone was silent, awaiting the maniac’s next words.
“Thank you, Monsieur” Regulus responded, bowing his head in deference.
The french term served as a good excuse not to acknowledge the self appointed lordship of the man without creating too big a spectacle.
Voldemort nodded approvingly and patted the seat next to him at the table, “join me, boy. Let us talk and dine, Lord Black”
Regulus did as he asked, sitting down in the chair, back straight, elbows at his sides and eyes turned downwards towards the table. The man seemed to appreciate the boy’s obvious shows of respect. A mean smile was curling his thin-lipped mouth. The Black heir was reminded of a particularly disturbing snake.
“Now, let us discuss my cause. I am sure you have been duly informed,” Voldemort began.
Regulus simply nodded in response.
“A man of few words? Pleases me just fine. If you agree with my goals, you shall receive the gift of my mark upon sunset tonight,” the Dark Lord offered.
“I am most grateful, Monsieur,” Regulus responded in turn.
The party, consisting of his cousin Bellatrix, his parents, his cousin-in-law Lucius and the man himself, all seemed extremely pleased at the development.
That evening, in the parlor of Grimmauld Place, Regulus kneeled before Lord Voldemort. He held out his bare forearm, eyes trained on the floor beneath him. Bella had told him it would be a magnificent burst of pain and pure power through his entire body. She said it would connect him to their lord by an unbreakable rope of magic.
Voldemort wielded his magic wordlessly, only using a wand for effect. He lightly placed the tip just above Regulus’ wrist and let the magic pour into the boy. It was something he had already done many times over. He took a sick kind of pleasure in letting his magic create the symbolic design and imbue it with a smidgen of his power.
Regulus could feel the moment that Voldemort’s magic entered under his skin. It was searing hot and felt like his skin was being pushed up by needles from below. It felt like that time mother had hit him with a hot poker except it was longer. Much longer. He did not cry. The younger Black brother had cried his last tears when his brother left. Since then, it was like life had become merely a nightmare he couldn’t wake up from.
So he endured. He didn’t cry when the mark finally bled up to his skin. He didn’t flinch when Voldemort sent more of his magic into it. He kept his eyes on the ground, mind drifting to a far off place.
It took one or two meetings before Voldemort trusted him enough to welcome him into his study. Regulus was smart and shockingly good with numbers for someone who had never received advanced mathematical instruction. Voldemort quickly came to appreciate his talent for running the numbers on any given situation.
Every day, Voldemort came to him with letters and proposals to the point where he acted as a secretary for the maniac. This position should not be underestimated and Regulus knew as much. When Voldemort was out, he used the time to look through papers and documents. Anything he could get his hands on. The Black library had an extensive section on spying charms that helped him leave everything the way he found it.
Within little to no time, he stumbled upon some research about the Hogwarts founders’ items. He had been looking for the secret to Voldemort’s power, and the heirlooms of four of the greatest magical folk of all time would probably be a good start. He prepared a list of likely hiding places, Hogwarts, the Gaunt family shack and Voldemort’s childhood residence being the top three contenders.The self obsessed megalomaniac would definitely make sure to choose important and sentimental places.
Since he was due back at Hogwarts regardless for his last year, Regulus decided to start with the Gaunt family home while he was still on break. He planned the trip, bringing all the best protective artifacts in the Black vaults and replenished a kit with healing potions. He was not risking dying so close to uncovering the secret to Voldemort’s longevity and power.
It was late, the sun had already set, as the heir of the Most Noble and Ancient house of Black approached the Gaunt family shack. The place looked more like a ruin than the residence of one of the descendants of Salazar Slytherin himself. Regardless, Regulus approached with utmost caution beneath the cover of night.
He snuck in through a back door. The place seemed empty. There were no sounds nor voices and the Homenum Revelio didn’t detect anyone. Slightly relieved, he made his way in and cast a charm to detect dark magic. The entire shack lit up with a faint red light.
“Great”, he thought, “of course this place is flooded with dark magic. I should have expected as much.”
Luckily, the spell amplified light in proportion to the wicked magic present and a spot on the floor looked like a beacon. Regulus walked over and inspected the floor. There was no apparent opening, so he pried the plank off and cast a quick Lumos. There, under the floorboards, was a small ring box. Taking it out, he found the heir ring of House Gaunt.
Elated at having found one of the artifacts, he slipped it on his hand and cast a quick glamour. He felt the evil magic seeping into his skin and blood. It flooded through him with an approximation of the feeling of receiving the Dark Mark. It stung and persisted, but he had to keep the artefact close and safe.
By the time Regulus boarded the train for Hogwarts, his cheeks had sunken and his skin was paler than it had ever been. There were noticeable bags under his eyes and he had lost a lot of weight. His ribs were clearly visible. A couple glamorous kept most of the stares at bay, but Evan and Barty noticed something was not right.
“Reg, what’s up with you?” Barty asked him when he hadn’t said a word to them for half an hour.
“Nothing,” Regulus replied curtly.
“Is this about that brother of yours? The Gryffindor. Heard he got disowned” Barty continued.
Regulus’ eyes snapped up to his friend’s with sudden apprehension and anger. He pushed his sleeves back, as if initiating a fight. Barty held his hands up in surrender before his eyes fell to Regulus’ forearm.
“Oh Salazar’s own snake! No way you actually got it before even being of age!” Evan exclaimed in admiration.
Regulus shrugged and covered it quickly. He turned to look out the window and didn’t respond to any more of their questions. He didn’t know whether to feel like a traitor or betrayed. He was betraying his family and friends, or at least their ideals, but they had abandoned him. All of them. Evan and Barty had never once considered he didn’t just run into the fireplace or bump himself on tables. Sirius had left him as if Mother wouldn’t turn her violence on him. The young heir felt utterly lonely.
“Regulus Arcturus! Are you too good for us now?! Now that you’re heir?” Evan barked.
Regulus turned towards his longtime friend, “No, Evan. I’m tired, my apologies.”
Evan Rosier had the decency to look ashamed for his outburst, but Barty wasn’t satisfied, “you haven’t said anything about your summer? How was it? How is the Dark Lord?! Is he as powerful as they say?” he insisted.
“He is a very powerful man. I took care of his numbers” Regulus said dismissively.
Both boys gaped at him. How could he be so nonchalant about such a big thing? The younger Black brother had always been quiet and mysterious but this was a new coldness, even from him.
“Well don’t you worry! Barty and I are joining up as soon as we’re done with Hogwarts and then we can all go on raids together!” Evan said enthusiastically, and Barty nodded in agreement.
Regulus did not say anything in response. He could not well just tell them their ideals were misinformed and their trust misplaced. Oh how he wished his friends were good people. Like Sirius and his group of misfits. Regulus often wondered how his brother had found a way to smile at Hogwarts when he was still hiding bruises of Wallburga’s punishments and Cygnus’ teaching. It was one of the reasons he admired his brother and why he missed him so much.
Evan and Barty were tempted to interrogate Regulus about his summer, but to their shame, and the heir’s relief, the train arrived at Hogwarts. The students poured out onto the platform and the first years were being led to the boats. Regulus watched the giddy smiles and nervous frowns on their young faces and felt a bolt of pain to his heart. Had he ever looked like that? He distinctly remembered Mother coaching him never to show his thoughts and feelings on his face.
The feast was an uneventful affair. The first years were sorted, the headmaster gave his usual welcome and the tables filled with food. Regulus ate little and pushed it around on his plate. His affliction would inevitably make him empty his stomach in the bathrooms later. His friends were too busy making comments about the Gryffindors and bickering with the girls to notice.
In the first week of classes, Regulus spent every afternoon searching the castle for possible hiding places. He tried his best to find the Chamber of Secrets but had no luck. Either the place was really a myth or it was so well hidden that it would take ripping Hogwarts apart to find it. When he wasn’t running around the castle in search of a diadem, a cup, a locket and a sword, he was in the library. He researched ways to destroy whatever the objects held. Regulus created a set of spells and charms to help him locate out of place or recently placed items.
The black heir grew thinner by the day. He was malnutritioned and sleep deprived but still pushing himself to go to classes and search the castle. Sometime after the first month, his grades started to drop. Slowly. He noticed but tried his best to make it look like he was simply getting lazy now that he was the sole heir.
Every day, it got harder to get out of bed. Regulus’ body was getting weaker and starting to fail on him randomly. He felt an overwhelming blanket of sadness pushing him down at all times. Old pictures of Sirius and books no longer helped. More often than he used to, he found himself wishing it could all just end. That it could all stop hurting.
After three months at Hogwarts, with no contact from Sirius and plentiful contact with his mother, Regulus was done. He sat in his dorm room at a desk and penned a note to Sirius.
“Dearest brother,” it read.
“I hope you are well. Wherever you are, stay safe and take care of yourself” he started before burning it and starting again.
“You left me. For this, I forgive you. You are now sole heir to the house of Black. Do something useful with all the money, won’t you? Find happiness if you can, brother of mine.
May you experience enough love and joy for the both of us. I am sorry I couldn’t protect you better and that you had to leave.” he tried again before groaning in frustration and burning this one too.
In the end he settled on a short note including only the most relevant and not burdening his brother further.
“Sirius,”
“This ring is a magical component that holds secrets to Voldemort’s power. I did not manage to destroy it. Do not wear it but figure out how to break it. Ask those smart friends of yours. It's imperative that you find a way.
Please forgive me,
RAB”
Using a spell he had researched and adapted, Regulus stole a random average looking owl from the owlery and charmed her to be untraceable and as good as invisible. He sealed the letter with blood magic and charmed the ring onto one of the owl’s legs. Letting it go, he watched it fly away.
“Farewell, mon frère” he whispered towards the stars and climbed up to the Astronomy tower.
Looking up at the evening winter skies, Regulus looked for Canis Major and there, the bright glowing Sirius.
“I miss you” the boy cried and let his tears roll down his cheeks.
The usually composed and collected Black stood at the wall of the astronomy tower and sobbed at the stars. His parents must have cursed him when they named him after a blue star. Standing on the ledge he sent a quiet prayer to the heavens that he would see his brother again someday. Regulus sighed and gravity did all the work.
For a beautiful moment he soared, eyes trained on the starry sky, heart suddenly light. He breathed out in relief and closed his eyes.