Regulus didn't follow Sirius when he ran from home. He stayed. He lived in the Grimmauld Place a year longer than his older brother. It wasn't ideal.
It was cold, empty and lonely. But Regulus adapted like he always does. His parents were cruel. But they were even crueler when Sirius Black left.
So, he lowered his head and did as he was told. He listened to everything they said. There were a few times when he stepped out of line after Sirius left.
And he was punished with an Unforgivable. After that, he learned his lesson. He didn't disobey, he didn't disrespect, he didn't do anything his parents disapproved of.
Regulus Black quickly became the perfect little future Heir of the Noble House of Black.
And then came the year when he would start visiting Hogwarts. His parents had sat him down and reminded him of what would happen if he were to be sorted into anything other than Slytherin. They reminded him not to disappoint them.
And Regulus, as young as he was, was terrified of disappointing his parents. So, when he did come to Hogwarts and the day came when the Sorting Hat would be put on his head, he fidgeted. Hours before he had reconnected with his brother in the hallway.
The two hugged each other and held onto one another tightly. Regulus told him of his fear of being sorted into Slytherin. Sirius reminded him that nothing would change if he did get sorted there. He loved him anyways.
Regulus held onto that fact while he walked towards the Hat. He didn't dare look at anyone. He was torn. Which was worse, he wondered.
Disappointing his parents or disappointing his brother? He thought about it and realized that disappointing his parents would be worse than a death sentence.
He had no other choice but to beg the Hat to sort him into Slytherin. And so he sat on the chair while everyone stared including his brother and his friends.
He felt James Potter's gaze on him and blushed a bit, not understanding what was happening with him. He closed his eyes once the hat was placed on his head and begged it to sort him into slytherin.
If the Hat heard him, it said nothing of his thoughts.
"Interesting. Another House Black Heir." The hat exclaimed first and Regulus heard murmurs.
He knew that they could not see a hint of panic on his face. His parents taught him how to control his emotions and expressions. But inside, he was dying. He gulped and waited while the Hat murmured before it yelled.
"Slytherin!" It said.
Regulus opened his eyes, terrified of looking at his brother and his friends. He looked at the Slytherin table to see them cheering and making wolf whistling sounds.
Barty and Evan who he met earlier and actually liked were sitting there too, cheering for him. Regulus gulped and sat up once the hat had been removed from his head.
He made his way to the table and sat down next to Evan who gently patted his back in encouragement. Regulus finally dared look at his brother.
Sirius had a conflicted expression on his face. It was clear he did not like the fact that Regulus was a Slytherin but he also did not want to lose his brother again so he sent him a small smile. Regulus knew they would be okay then. He did not dare look at James even if he felt the Gryffindor staring at him.
Things were as good as they could be afterwards. Sirius assured him they would be fine. And so Regulus hang out with his friends and with Sirius and his friends often.
Barty, Evan and Pandora had become close and important people in Regulus' life. Sirius learned to respect that.
It did not take long for Regulus to fall for James. It all started when Regulus started spending more time in the library with Remus Lupin who he was sure was in love with his brother. Regulus already knew Sirius liked Remus.
The Older Black brother confided in him once. Anyways, Regulus' reading and studying had often been interrupted by James who seemed eager to start a conversation with him much to Regulus' confusion. Only a year after the flirting started, James dared ask Regulus out in front of his own brother. Sirius had been shocked to find out they even liked each other. But then came the shovel talk.
"James, hurt my little brother, and I will kill you." Sirius said before he turned to look at a shocked Regulus.
Remus was sitting beside him, smiling with Peter at the whole ordeal.
"Regulus, hurt my best friend, and I will kill you. Please do not make me choose between the two of you." He said and Regulus only nodded his head even if James looked ready to jump out of his skin from happiness.
And then the dating started. They used any chance they found to make out. At the Astronomy Tower, in the dorms, in the dungeons, in the woods. Anywhere.
James adored the younger Black. Regulus was smart and kind behind all that mean facade he had going on.
James knew it and saw it the first time he met the younger of the Blacks. Everything was perfect for a while. James and Regulus really did love each other.
Even a blind man could see so. James was soft and careful with Regulus, almost as if he was afraid he would break him.
And the younger Black felt happiness like never before, glad that someone finally showed him what unconditional love looked like.
But then it all went wrong...
Regulus cried when he entered his dorm room. He tried not to wake anyone up. But Barty and Evan woke up the second they heard him sobbing in his bed.
"Regulus? What's wrong? What happened?" Evan called out and he stood up from his bed. He walked up to Regulus and sat down on his bed, tugging on the covers that were hiding the broken Black brother.
"Reggie? Come on, man, what's wrong?" Barty called, now worried as well. Regulus never cried.
Not even his parents could make him cry anymore so what the hell was going on now? The two Slytherins looked at each other in confusion. Evan shrugged his shoulders.
"I- I told Sirius they made me do it. He didn't believe me. Neither did James. They- they told me to get lost- and to never come to them again." Regulus cried and Barty felt his anger levels rise up. He stood up from the bed immediately and took his wand, ready to go out in the middle of the night and curse the Gryffindors.
"Made you do it? Who made you do what?" Evan asked and Regulus now sat up. Barty's eyes widened when he saw that his arm was bleeding and he stepped forwards, pulling his sleeve up. Both Evan and Barty gasped at the sight of the Dark Mark on Regulus's forearm. Regulus only continued sobbing even more now.
"I didn't want it, I swear it. But they- my parents didn't listen. They held me down while he-" Regulus sobbed and Evan pulled him into a tight hug. He looked at Barty who looked a second away from murdering someone right now.
"I'm not like them, I promise-" Regulus swore through his cries and Evan hugged him tighter.
"I know. We know you're not. We believe you. The Marauders may not but I do. Barty does. And Pandora will too."
"I can go curse their entire house right now." Barty said and Regulus shook his head.
"Don't! Please!" Regulus asked and Barty planted his feet where he was standing.
If Regulus did not want him to go destroy his brother and his friends, he would not even if he itched to do so.
He came to stand beside Regulus's bed and crouched down so that he could look him in the eyes while he was still hugging Evan as if his life depended on it.
"Here is what we do from now on then." Barty said and Regulus's eyes met his own. And so Barty came up with a plan. Regulus would try telling them the truth one more time. If they didn't listen, it was their loss. Regulus would ignore them too from then on. He agreed reluctantly.
The following day, he stopped the Marauders and tried talking to them. No one listened to him. Not even James Potter who always listened to what he had to say.
Sure, he had to be pulled away from him by Lily but still- he didn't listen. Once sadness passed, all Regulus started to feel was anger.
Anger at his brother who promise he would not abandon him again.
Anger at his parents for forcing the mark on him.
Anger at James who refused to see the story from his point of view.
Regulus started to ignore them too. He pretended they did not exist. Any time someone would compare him to Sirius, he would curse them and tell them to stop since he had no brother to be similar to. Sirius heard this a few times and felt his words cut into his heart but made no move to correct him.
Regulus had become like their parents. Sirius no longer wanted to have a brother. Now, whenever the Slytherin friends wanted to prank someone, they directed their energy at the Marauders. And this time, Regulus did not stop them.
The younger brother Black refused to sit anywhere near Lupin anymore. And the few times when Remus tried to sit down with him like in the old times, Regulus got up and moved to a different table, ignoring the hurt looks Remus would throw his way.
Regulus Black no longer cared. He needed to find a way to cut the mark off his arm. He made notes and read countless books. Hell, even his friends came to help him a few times. Pandora was the one who came across a book on Horcruxes. When he saw what she had found, he took the book and ran out of the library, ignoring the looks he got from the librarian, his friends and the Marauders.
Regulus ran to Dumbledore and he told him everything. The entire truth. From that day on, Regulus worked as Dumbledore's spy in the war. No one knew. No one but Regulus and his three friends. And they were sworn to secrecy. After a while, Sirius started getting worried when he noticed how exhausted Regulus looked. He tried approaching Evan about his worry and was not met with a friendly face.
"What do you care why he's exhausted. You no longer have a brother, remember?" Evan called with a smile on his face and he walked away, leaving Sirius alone in the hallway to wonder if what he did was right. Still, Sirius continued to worry and he tried talking to Barty too but Barty refused to even acknowledge him. Then he went to Pandora with James, wondering if James' friendly face would make her spill the beans. She did not. She only looked at them both with indifference on her face before she spoke.
"You should try talking to Reggie if you're worried." She had said and walked away. Sirius refused to acknowledge the pain he felt at the sound of the nickname she used for his brother. Once upon a time, Sirius was the only one allowed to call Regulus Black 'Reggie'.
The day when it all changed its course was when they were all at breakfast. Regulus had been laughing at something Barty said, feeling the eyes of both his brother and James on him but refusing to acknowledge either of the two. Then suddenly, Kreacher appeared on the table beside him and Regulus frowned but moved his head towards him so that he may whisper to him. His eyes widened at whatever it was Kreacher said and he nodded his head.
He looked at Barty and then whispered something to Pandora who immediately nodded her head with slight fear in her eyes. Sirius looked at James who shrugged his shoulders and looked at Regulus again. They could hear a part of the conversation now since Regulus was walking with Barty and Kreacher towards the exit of the hall.
"If you end up needing help, you call us, do you understand? Tell me you will call us, Reggie." Barty practically begged and Regulus rolled his eyes but nodded his head anyways.
"I won't need any help but if I do end up needing it, I will call for you. I promise." Regulus said and walked outside.
Barty took a deep breath and walked back to the table. James looked at Sirius who only nodded his head and the two got up and left too without being noticed by the Slytherins. They followed Regulus who walked through the hallway with Kreacher, towards Dumbledore's office. Sirius frowned when he saw Regulus enter it without knocking. Sirius ran up to the office and leaned against the door, to listen in. That is when they both heard the concerning conversation.
"It is time to do as I said I would." Regulus had said and Sirius frowned. What did he have to do? And why did it feel like the Slytherins were saying goodbye earlier?
"Are you certain you wish to do this alone, young Black?" Dumbledore asked.
"Of course I am. Let me go now and I will be done by sundown." Regulus could be heard talking. The rest of the conversation was silent than the beginning hence why neither James nor Sirius understood what was going on.
"Are you certain you do not wish to bring help? Maybe your brother and his friends? Or your own friends?" Dumbledore asked one more time and Regulus could be heard sighing.
"I have no brother and I said no already! I am not putting any more lives in danger!"
"Any more lives? Does your life not matter, Regulus?" Dumbledore asked and Regulus frowned.
"I go alone. Or I do not go at all."
"Very well."
"Make sure the Marauders do not follow me. And also make sure my friends do not come after me." Regulus said at last and began moving. Sirius and James sprung from the doors so that he would not think they were eaves dropping. Regulus closed the doors and stopped when he saw them at one of the benches in the hallway. He glared for a couple of seconds before he started walking again.
"Where are you going?" Sirius called. Regulus turned around and glared at him. Gone was the warmth that was once in those dark eyes.
"None of your business." Regulus answered.
"Does this dangerous thing have something to do with why you took the mark?" James asked and now Regulus looked angry. He glared at James. He GLARED at James Potter. Sirius did not think that was even possible.
"Now you want to know of my Mark? A year after I came to you and begged you to hear me out?" Regulus asked and Sirius frowned.
"What other reason other than you being like our parents could there be for why you took it?" Sirius asked and Regulus smiled. Regulus fucking smiled at him. And it was the most unsettling thing he has seen as of late.
"You'll find out why I took the Mark soon enough." Regulus said before he continued walking with Kreacher who was glaring at Sirius. What the fuck had he done that was so bad? Why was even his house elf glaring at him? Why did it seem like the Marauders were in the wrong here? They were never in the wrong. Just as he was about to suggest to follow Regulus, he disappeared. he just disappeared into thin air.
"Did we do the right thing all those months ago, Siri?" James asked Sirius in a small voice. Sirius turned to look at him and frowned.
"No way. We can't have been in the wrong, James. He took the Dark Mark. What excuse could he possibly have?" Sirius asked just as Barty was passing them by and going to the Dumbledore's office. He had red pain on his clothes. He must have played a prank and it backfired.
"You have no idea-" Barty had told them in the passing and entered the office.
Hours passed. And then days passed and Regulus was still gone. Sirius was growing more and more worried by each passing second. James could not stop pacing and judging by the looks on their faces, the Slytherin friends were not calm either. Barty's leg would not stop moving under his desk. Evan could not stop zoning out. And Pandora looked on the verge of tears all the time. They hadn't laughed or smiled even once since Regulus disappeared. James observed them for days, Pandora had even started chewing on her nails. James lost the count of how many times Evan had to slap her hands in order for her to stop. Her silver eyes looked worried and spaced out. Finally, a day came when Sirius and James had enough. They sat down in the library with the Slytherin friends of Regulus and demanded an answe.
"What the hell is going on? Where is Reggie?" Sirius demanded answers and Barty glared his way.
"You lost the privilege to call him that when you didn't want to hear him out a couple of months ago." He spat out and Sirius glared.
"What was there to hear out? he took the Dark Mark! He is like our parents!" He growled out and Pandora turned to glare at him. It took a lot for her to grow angry. And now, she was fuming. Evan sensed this in his zoned out state and he snapped out of it, putting a hand on her shoulder to calm her down.
"Like your parents? LIKE YOUR PARENTS? Regulus was forced to take the Dark Mark BY your parents! He came to you to ask for help but you shunned him. WE were the ones who stayed by his side. We were the ones who comforted him in his grief of the loss of his brother. We were there when he cried from agony when the Mark would affect him. You have no right demanding answers now, Siri!" Pandora yelled, ignoring the fact that they were in the library.
"What?" James asked, his eyes watering, regret and pain was so clear in them now. But Pandora no longer cared. They all hurt her friend because of their selfish ignorance.
"That can't be." Sirius whispered, refusing to believe that his brother came to him for help and he had pushed him away.
"But it can. Walburga and Orion Black held Regulus down while the Dark Lord put his Mark on him." Evan said, his voice calm but anyone who knew him well enough could see the storm in those eyes.
"Where is he?" James growled out and Barty smiled sadly.
"Who knows? You refused to help so he went to the only person he knew he could count on in some way. He has been acting as Dumbledore's spy since. You want to know where he is? Ask Dumbledore!" Barty barked out and James immediately got up and started running with Sirius following him closely behind.
They marched into the office and it took all of his control for James not to jump over the table and strangle his principal right now. Sirius was the same judging by his tense shoulders and the frown on his face.
"Is it true?" Sirius asked calmly.
"What?" Dumbledore asked, confusion etched onto his old face. James frowned now too.
"Is it true that Regulus was your spy this entire time?" James asked. Dumbledore hummed and leaned back into his chair.
"It is." He answered, not seeing a reason behind lying any longer. Regulus had been gone for two weeks now. For all he knew, the young Black was already dead.
"Where is he now?" Sirius asked, calm still on his face.
"Kreacher found the final Horcrux of the Dark Lord. I sent Regulus to deal with it. He insisted he could deal with it alone. But he has been gone for a few weeks now. For all I know, he could be dead." Dumbledore admitted and James growled. Sirius took a wooden chair and threw it against Dumbledore's wall, making the principal flinch in surprise, not realizing that even when in fight, Sirius would always care for his little brother. They could bicker and fight and tear each other's heads off. That did not change the fact that Sirius Black loved his little brother.
"You sent my brother into his death all alone?" Sirius asked and Dumbledore only continued watching him.
"ANSWER HIM!" James yelled and then the doors were thrown wide open again.
Everyone's eyes widened in shock at the sight of who it was. A bloodied and beaten up Regulus Black who looked like he was barely standing on his own feet.
He had a bag over his shoulder and his other hand was holding a blanket that he was dragging across the floor. He did not pay either James or Sirius any attention.
He was breathing hard, still in pain from the fight he barely survived. He stopped once the blanket and whatever was inside was in front of Dumbledore's desk.
The principal got up and started walking around the desk to see what was going on. Sirius and James ran up to Regulus and were about to help him sit down when the wizard pointed his wand at them and pushed them away.
They all watched Dumbledore open the blanket to see a beaten up and very much dead looking Voldemort inside. James and Sirius immediately took out their wands. But they all turned to look at Regulus when they heard him opening the bag. He turned the bag upside down and the contents of it started pouring out. All of the contents were broken but it was clear what it was. Voldemort's Horcruxes. All seven of them destroyed. Their eyes widened and they all looked at a swaying Regulus who let go of the bag then.
"Told you I could do it alone. Do with that what you will." Regulus said and began walking away, towards the exit of the office.
It was clear what had happened and where his brother was now. Regulus had destroyed all of the Horcruxes alone and then he killed the Dark Lord on his own in a span of two weeks. James was the first to move outside, after Regulus while Sirius remained planted in his place.
"Do me a favor, Sirius and spread the word that the Dark Lord is dead." Dumbledore said and Sirius snapped out of it now. Voldemort and his Horcruxes were now on the floor, burning. Sirius ran after James only to see Regulus who had stopped in the middle of the hallway. Barty, Evan and Pandora stood before him, their eyes wide in disbelief. Pandora was the first to move.
"You did it! I knew you could do it!" She said and sniffled while she pulled him into a tight hug.
Regulus flinched and she immediately let go of him. She took a step back and looked at him in worry while he swayed on his feet. And then the worst happened, Regulus started falling. His knees gave out and James rushed forward, catching him just before he fell on the floor.
He sat on the floor of Hogwarts with his lover in his arms, wondering if he was alive or dead. He wondered if he would have a chance to fix what he broke when he refused to listen all those months ago. Or would he lose Regulus forever? Sirius could not move, wondering if all of this was his fault. Was his brother dying because he did not believe him back then? Evan ran up in worry and he dropped to his knees beside Regulus, immediately putting his hand on Regulus' neck, looking for a pulse. They all waited.
"It's still there! I can feel it!" He yelled and James' shoulders sagged with relief, wondering if Regulus could survive this?
Would he give him a chance to talk and explain himself when he woke up? Or would he really break up all of the connections he had with the Marauders? Sirius remained planted where he was, unable to move, feeling the guilt rising up to his throat. No one was sure what kind of person Regulus would be when he woke up. But they all knew one thing for certain. Regulus Black had become the war hero.