Chapter Text
James and Lily Potter had never intended to get four kids. No, they had a completely different plan. Just one kid for now, maybe in a few years another one if this horrible war ever ended. A really simple plan. They had even already decided on a name. Harry James Potter if it was a boy, Daisy Lily Potter if it was a girl. That plan was completely and utterly destroyed the moment they discovered that Lily wasn’t pregnant with just one, but four kids. Four identical quadruplet boys, to be exact.
Months later, Alan, Alex, Adam and Andor Potter were born. Sufficed to say, caring for four young babies was a little tiring. It became only worse when they had to go into hiding. So, when Peter mentioned he wanted to throw a small little Halloween party with just the Marauders and Lily, Sirius was glad. Lily and James deserved a break, and Sirius was going to make sure, whatever it took, to make them go.
It took a lot of convincing from both Sirius, Remus and Peter, but eventually, Lily and James cracked. So, on Halloween evening, they left, leaving Sirius behind to care for the kids. The first half of the evening went wonderfully. Sirius watched some weird muggle thing called TV, after that he made some amazing tasting food, although Adam really didn’t like it for some reason, and he even started reading one of Lily’s muggle fantasy books.
But even though everything was going well, Sirius was feeling tense. He couldn’t explain it. Well, he guessed he could probably explain it. The fear of You-Know-How barging in and brutally murdering the babies was continuously on the back of his mind. It had already been stressful the past few months, knowing He-Who-Must-Not-Be-Named was after James, Lily, and the kids, but none of that compared to actually being stuck in the house, being the sole person responsible of the well-being of the kids. How did James and Lily manage to life with this? Maybe they just got used to the constant fear and stress. Sirius certainly hadn’t gotten used to it. He felt paranoid; every little sound set him off. His fingertips were constantly around his wand, ready to draw it.
It was getting pretty late, so Sirius decided it was time to put the boys to bed. Andor, Alex, and Adam were already quite tired looking, although Alan kept cheerfully dancing around. Sirius chuckled. Truly a godson of his. After walking down those annoying creaking stairs a few times, Sirius managed to get all the kids upstairs in their room.
But then, just when he walked inside with Andor, he felt something. It was at the very back of his mind, a light tingle. Had Sirius not been on edge so much, he probably wouldn’t even have noticed. But he did notice, and knew exactly what it meant. The outer defence ward, the one that he put up, the one that was supposed to stun anyone who came too close to the house, had been broken.
Sirius felt the first feelings of panic break out. It had to be him. Think clearly, he told himself. He had around thirty seconds before Voldemort succesfully broke the other charms and would enter the house, Sirius guessed. He needed to hide the kids. He quickly ran towards Andor’s bed and put him down. Sirius walked a bit back and murmured a silencing charm. Then he walked out of the room and cast a locking charm on the door.
He needed to warn Dumbledore, he then realised. "Expecto Patronum", he said quietly, and quickly added: "He is here, come now". Dumbledore would understand. 20 seconds left. It would take at least a few minutes before the patronus arrived, in that time Voldemort could easily find the kids.
He needed to somehow delay You-Know-How. He couldn’t face him head-on, Sirius knew. It would lead to his very quick death, and You-Know-How would still find the babies. No, Sirius needed something smarter. There was no way he was going to let the babies get hurt on his watch. He had promised James- wait, James. James had an invisibility cloak. With James’ cloak, he could sneak up on You-Know-How and take him from behind. He turned around and ran into James’ room. Luckily, James wasn’t very tidy, so his cloak lay in a corner on the ground. 5 seconds left. Sirius picked up the cloak and put it on.
The front door flew open. Sirius cast a non-verbal silencing charm on himself and ran into the upstairs hallway. He could hear You-Know-How walking downstairs. Sirius tried to ignore it and tried to think of a spell to use. He needed a spell he could do first try non-verbally that could take Voldemort immediately out. Anything else would give him the chance to react.
Stupify, the stunning spell, he thought to himself. However, he quickly dismissed that idea. There was no way someone as competent as You-Know-How wouldn't have done some basic blood magic to render himself immune, or enchanted his cloak, or did one of the thousand other easy things to permanently protect himself for the most simple standard duelling spell. No, Sirius needed something better. His next thought went to the piercing curse, Percutio. If he hit Voldemort just right from behind so his heart would get pierced, You-Know-How would be down. But Sirius wasn’t too much of a fan of that idea either. If he missed even the tiniest bit, Voldemort wouldn’t be instantly down and be able to fight back, heal himself, kill Sirius the boys, and other probably very unpleasant things. It was just too risky.
But when he saw Voldemort walking up the stairs, getting closer to the boys he had sworn to protect, he knew he at least had to try. So, he moved towards the wall, and sneaked past You-Know-How. He drew his wand. If Voldemort looked behind him now, he would see a wand tip floating in mid-air. Instead, he laughed at Sirius' pathetic lock, and opened the lock on the guest room door with a simple flick of his wand. Percutio, Sirius thought, and the Dark Lord Voldemort fell to the ground.
Was he still alive? He didn’t seem to be moving. Sirius ran towards him and felt his pulse. Nothing. Sirius sighed in relief. It was over, wasn’t it? And not even in an epic grand battle or a spectacular final siege. Voldemort didn’t even have the time to think about fighting. Sirius just sat there, he didn’t know how long.
And then, he heard the front door open. Sirius stood up again, his wand shakily in his hand. It had to be Dumbledore, right? Just to be sure, he covered himself once again in James’ cloak, silently awaiting the newly arrived person.
“Sirius?”, he heard suddenly in front of him. Dumbledore’s voice. Sirius kept on the cloak. It could be a Death Eater. “What did you tell me when I asked you in your seventh year if you wanted to join the war effort?”, Dumbledore’s dislocated voice asked. “I said ‘of course, idiot’. What did you say when James and I sneaked into your office in third year?”, Sirius replied, keeping his wand focused on where Dumbledore’s voice was coming from.
Dumbledore appeared from thin air, clearly having cancelled his invisibility charm. “I said ‘I heard you coming from three miles away’, Sirius”. Sirius threw off James’ cloak. Dumbledore’s expression became a lot more serious. “What happened?” he asked, looking at You-Know-How’s dead body.
So Sirius quickly told the story, of how he managed to take down Voldemort with a piercing charm. Dumbledore looked impressed, but quickly focused his attention on Voldemort’s body. His expression darkened. Sirius followed his gaze and realised what he had noticed. Voldemort’s fingers were starting to crumble. Silently, they both looked at the slowly disappearing body.
“Dark magic”, Dumbledore guessed. “He used a lot of dark magic on his body. Blood magic, probably”. Sirius nodded. That made sense. Then, he had an realisation, a thought he hadn’t even considered until now. “How did You-Know-How get here?”, he wondered out loud. The fidileus charm should have hidden the spell. Peter. There was no way Peter could have told him. Absolutely no way. Little muggleborn Pete who would cry because of the smallest things would never. However, Dumbledore said the thing that they both deep down knew. “Peter. He betrayed them”. Peter had told. Peter, muggleborn Peter had told the dark lord where to find James, Lily and the kids. That Halloween party Peter was hosting right now, that wasn’t just a Halloween party. It couldn’t have been. Peter had told. Was he torturing Lily and James for info right now? No, Peter wouldn’t do that. Peter wouldn’t tell. But he did. Peter had told. The one day James and Lily weren’t there, You-Know-How attacked. Because Peter had gotten them away.
Peter had told. Peter had condemned him to a likely painful death. Peter had condemned four babies to a painful death. He had condemned his own godson to death! Peter wouldn’t do that. He wouldn’t tell, he was muggleborn. The charm must have worn off. But Dumbledore cast it, and he said it was Peter. Peter had told. Muggleborn Peter had helped the Dark Lord. “Keep breathing, Sirius”, Dumbledore said next to him. Peter had told. Then, he stood up. “We need to get to James and Lily right now. Yes, they did. Peter had told. They needed to inform James and Lily. Peter had told. They needed to catch Peter. No, the traitor. Not Peter, just a traitor. Then it hurt less. They needed to catch the traitor.
“Remus’ cottage. We can get there via the fireplace of the neighbours”, Sirius said quickly. “One of us should stay with the kids”, he then said to Dumbledore. Dumbledore immediately asked: “Can you take on Peter?”. Sirius nodded, he could definitely take on Pet- the traitor. The traitor. “I’ll stay with the kids, you get Peter. I’ll inform the ministry of what happened”, Dumbledore said. Sirius nodded, put on the cloak again and rushed downstairs. Now that the wards were destroyed, he could walk outside the building with ease. No delicate password whispering and temporary counter spells.
He whispered a simple locking charm to open the front door of the neighbour’s house. Matilda wouldn’t mind. He kept the cloak carefully on. Luckily Matilda had some flew powder next to her fireplace. “Remus’ cottage”, he whispered, and threw the flow powder on the fireplace. He stepped inside, and everything started turning.
Sirius stumbled out of the fireplace 50 metres or something from Remus’ cottage. Remus had always focused on safety. An anti-apparition ward so big that it almost matched that of the orders Headquarter, only one fireplace far enough away from the building to see any attackers coming, multiple wards. Normally, Sirius could appreciate, but now it only was frustrating. He ran, but was careful to keep the cloak on. Otherwise, if P- the traitor was looking outside, he could see Sirius coming.
And then, he stood in front of the front door. Sirius knew he had to be smart right now, just keep on the cloak and knock him out. But the weird calm he had been feeling just moments before was starting to fade. Peter had told. How could he. A raging fire burning through his head. How could he have betrayed them. There was no way Sirius could just quietly and quickly knock him out. He needed to know why. Peter had told. How could he have betrayed them.
Sirius opened the door with the secret password. Remus had trusted his friends with it. He had trusted Peter with it. Would death eaters come here too? Sirius pushed those thoughts away. He needed to catch Peter. Sirius walked inside.
He could hear music echoing, laughter. Was Peter laughing too? He had told and he was laughing. How could he be laughing! He had told! James’ cloak fell off. Sirius didn’t bother to pick it up. A raging fire. How could he. Sirius kicked open the door. Sirius caught the faintest glimp of Remus, Lily and James and him looking very surprised. Before he knew it, Sirius had opened his mouth. The thoughts echoing through his mind finally came out. Peter had told. “How could you! How could you tell!”, Sirius screamed.
Peter looked at him with a confused expression. He had told. How dared he look confused! “What do-“, Remus began. “You know exactly what I’m talking about. You told”. “W-what?”, Peter stuttered. He had always been a good actor. Sirius grabbed his wand. Peter was quicker. “Bombarda Max-“, he started. But before Peter could finished, he fell to the ground. James wand was still aimed at the place he had hit Peter with a nonverbal stunning charm. He looked pale. “What on earth happened?”, Lily asked. Sirius casted another non verbal charm to ensure Pet- no, the traitor wouldn’t wake up anytime soon, and then tried to calm himself down.
He felt the eyes of Lily, James and Remus burning into him, but he couldn’t quite manage to open his mouth. He thought back to those fateful moments. To Voldemort walking right past him, getting so, so close to the boys. The sound of his body hitting the floor. “You-Know-How is dead”, he bursted out. “I killed him.” Sirius completely expected James to laugh, to assume it was some stupid joke, but no, James surprised him. Instead of doubting him, he remained serious for once. “What happened?”, he asked, and so, Sirius told once again the story he had told Dumbledore just minutes earlier.
James looked even paler by the end of it. “We need to get back now”, he said. Sirius looked at the unconscious Peter, trying very hard to stay calm and not lose his temper again. “Dumbledore said he informed the ministry. They are going to come to arrest him”, he said, not once moving his eyes away.
After a moment of silence, Remus spoke up. “You guys go back, I’ll wait here for the aurors”, he offered. “Let’s go”, James said again, and the three ran outside, in the direction of the fireplace. They ran, to get back to the house were Dumbledore was waiting next to the boys. The house, where Voldemort’s body was laying right now. They ran, not yet thinking about the many newspapers and parties still to come. Not yet fully realising how this day would forever be marked in history. Not yet knowing that from this day onward, Sirius black would be known as the ender of wars, the saviour of the Wizarding World. Sirius Black, the Dark-Lord-Slayer.