A/N: Based on a prompt from tumblr user h0lyheadharpies about Sirius falling through the veil into a parallel universe. Don't really have any other notes. Reviews are greatly appreciated. Hope you all enjoy!

Bellatrix sent a jet of red light at Sirius head and he ducked, laughing. He knew it would infuriate her, his dear cousin had always hated being mocked. Sirius also knew that while fury fired Bellatrix up for a fight, it also made her erratic, and if he could just throw her off balance…

"Come on, you can do better than that!" he taunted, loud enough for everyone to hear.

Bellatrix growled in response, and Sirius smiled, he was so close, any minute now she would lose it and start fighting more like a rabid animal than an intellectual dueler. Sirius opened his mouth again, another taunt bubbling on his lips, but another jet of red light hit him squarely in the chest before the words could spill forth. He felt himself lose control of his body as the stunning spell took effect and he fell backwards. He passed through something very warm, like a curtain of steam, and then hit the ground hard.

Sirius felt pain spread through his tailbone, and instinctively rubbed his hand over it as he sat up. It took a few seconds for him to realize that he should not be able to run his hands over anything. He had been stunned, he shouldn't be able to move. Alarmed, Sirius looked at his surroundings, even more surprised to find that he was no longer in the Department of Mysteries. He recognized his new surroundings immediately, and they sent a pang of sorrow through his heart. It was Godric's Hollow, the fountain in the center square to be precise.

Sirius looked around in confusion. How had he gotten here? Perhaps something in the Department of Mysteries had been a portkey. But then how had the stunning spell been lifted? A portkey would not do that. Sirius pushed himself to his feet and stepped closer to the fountain, staring at his reflection in the water. His face looked younger, with fewer lines and softer edges, as though the weight of grief and sorrow had been lifted from his body.

"Hey, you okay?" a voice said from behind him, and Sirius closed his eyes as he recognized it with ease. He turned to look over his shoulder and saw that Remus too looked younger, less troubled.

"This is wrong," Sirius said, gesturing toward the fountain, and he turned to look at it once more, as Remus slid his arm around his waist. "This shouldn't be a fountain, they took it out. They were going to build a monument, I read about it in the Prophet."

"I didn't see that, but I suppose they just haven't started construction yet," Remus answered, and Sirius saw Remus' reflection give him a curious look.

"No, it was thirteen years ago, after the first anniversary," Sirius insisted, running a hand through his curls.

"I don't know, love, maybe they just decided not build it after all," Remus shrugged, and Sirius flashed him an odd and somewhat irritated look. "Come on, we're going to be late."

"Late for what?" Sirius asked, his confusion mounting.

"Where's your costume, mister?" a little boy asked as he ran by, pausing to cock his head at Sirius.

"He's going to put it on at our friend's house," Remus assured the young boy, and he ran off, seemingly satisfied. "You did bring a costume, right?"

"A costume? Why would I have a costume? Remus we were just fighting –"

"I know we were, but I thought we could put that aside tonight for Harry's sake," Remus hissed. "Can't you just enjoy taking your godson trick or treating?"

Sirius looked around him again, taking in more details than he had before. In addition to looking younger, he and Remus were wearing different clothes than they had been at the Department of Mysteries. The air was cool and crisp, far different from the heat he had felt when he'd left for the Ministry. Leaves rustled as they skipped across the ground in the wind, and down one of the side streets, Sirius could hear the sound of excited children.

"It's Halloween?" Sirius said, more to himself than to Remus, as pieces of the puzzle began to fit together in his mind.

"Yes, of course it is, stop acting strange," Remus answered. "Come on, James and Lily are waiting for us and if we don't go soon, it'll be too late to take Harry out."

Remus didn't wait for Sirius to reply as he turned and began walking down the street that led to the Potter's cottage. Sirius considered all the evidence in front of him and came to a conclusion that distressed him more than he could say. He must be dead, and this was the afterlife. Sirius had never really believed in heaven and hell. The Black family was not particularly religious, and even if they had been, how could Sirius ever believe in a god after the kind of childhood he'd had? It was the only thing that made sense, the only way he could possibly be with James and Lily. He wasn't sure how it had happened, clearly not the stunning spell, but perhaps he had hit his head hard enough when he fell…

Oh god, Harry, Sirius thought, and his heart clenched painfully. His godson would be devastated at his loss, and the fifteen-year old had already been through so much. The idea of Harry suffering made Sirius' heart ache, and he felt an almost desperate desire to get back to him. How did one become a ghost? He had never much liked the idea of becoming a ghost, but if it meant not leaving Harry alone, it would be worth it. And Remus too… Sirius realized, if Remus was here, it must mean that something had happened to him too. There was something fitting about Remus dying moments after himself, in the same battle, but thinking of Remus' death made him hurt in indescribable ways. He wasn't sure whether or not he wanted to know what happened to Remus – he could imagine well enough, Remus charging Bellatrix when he saw Sirius fall, leaving himself vulnerable to a killing curse.

Remus stopped walking at the gate leading to James and Lily's house, his hand resting on the wood. It was exactly as Sirius remembered, and yet not. The hedge was about shoulder height, perfect to keep prying eyes from seeing little Harry flying around on his training broom. The stone of the house was neat, though here and there ivy climbed the cracks. James had hated the ivy, always saying he was going to take it down, but Lily loved it, she had thought it made the place feel more homey. The house looked different from the last time he had seen it though. The gate was hanging properly, not from its hinges, latched closed, and the door was not blasted ajar. On the second floor, the walls continued normally, when Sirius vividly remembered the wall of the nursery having been blasted apart, leaving broken studs visible. Perhaps the biggest difference, however, was the three individuals sitting on the front doorstep.

James, with his messy black hair, was holding Harry, and Lily sat beside them, one hand resting lightly on James' thigh as she smiled at her son. After a moment, she looked up and waved warmly at them, her green eyes sparkling welcomingly.

"You made it!" she exclaimed, rushing forward to hug them as Remus pushed open the gate.

Sirius felt his eyes well up as Lily's arms wrapped around him, the familiar scent of her perfume wafting over him. It had been so long.

"Sirius? What's wrong?" Lily asked him, suddenly alarmed. He hadn't even realized that a few tears had fallen.

"I've missed you so much," he answered, nearly whispering.

"Missed us?" she replied, shooting Remus a concerned look. "You were here a few days ago, Sirius."

"It's alright, Lily, you don't have to pretend to ease me into it or anything, I know what's going on," Sirius stated, pulling away from her and looking at James. "I know I've died. I just don't understand why it's like this."

"Died? Sirius, no one's died!" James interjected, alarmed.

"It's fine, James, really," Sirius insisted. "I don't regret it, I was fighting to save Harry from the Death Eaters, there's no more worthy cause –"

"Death Eaters?" Remus interrupted, and he, James and Lily all exchanged confused and concerned looks. "What are Death Eaters and why would they be after Harry?"

Sirius stopped and looked at his friends, noting the concern that laced their features. They were all regarding him as though he was a bomb about to go off, something alarming and unpredictable.

"How can you not know? Voldemort, he killed you, and now you can't even remember who he is?"

"We're not dead, mate," James said, holding onto Harry a little tighter. "I don't know what's gotten into you, but no bloke named Voldemort's ever tried to hurt us."

Sirius paused, looking at everything in front of him. It made no sense – if they were all dead, James and Lily should remember everything that had happened still, just as he did. And why would baby Harry be in the afterlife, when he had very clearly survived the attack? Something wasn't adding up.

"Are your parents joining us?" Sirius asked James, testing a new theory.

"No, of course not, mate, my parents… they've been gone for a couple months now," James answered, his voice catching a little bit, and he looked down at Harry, running his hand over the infant's head.

That settled the matter – he couldn't possibly be dead. If this were the afterlife, then anyone who was dead would be alive to them. James' parents had indeed died a few months before their son, so they would have to be here if it were the afterlife. The fact that they weren't, that this James' parents were dead too, meant that something else was going on.

"Right, yeah, I meant Lily's parents," Sirius recovered quickly, and Lily took a deep breath.

"No, Petunia convinced my parents that they should spend Halloween with their son," Lily said, sounding slightly bitter.

"I'm sorry, Lils," Remus replied, stepping forward to hug his friend. It seemed that even in this reality, things between Lily and Petunia were quite tense.

"Hey, you guys don't happen to have a copy of today's Prophet, do you?" Sirius asked, trying his best to sound casual.

"Not today's, but I think we still have yesterday's paper," James shrugged, handing Harry off to Lily and leading Sirius inside.

They went to the kitchen, where James dug through a pile of parchment and extracted the previous day's Daily Prophet, handing it to Sirius. He looked at the headlines, flipping through quickly. Every article looked benign, nothing that he remembered seeing, no sign of the events he remembered happening. In the week leading up to his Lily and James' deaths, the wizarding world had been buzzing about the disappearance of Benjy Fenwick, but there was no mention of it in this paper. There was simply no way this could be the same reality that he had lived in.

"James," Sirius ventured cautiously, unsure of how his friend would react, "do you believe in parallel universes?"

"You mean like a place where everything is the same except for one thing?" James clarified, sitting down at the kitchen table.

"Yeah, only one change can have a huge effect," Sirius persisted, and James nodded.

"The butterfly effect," he agreed. "I guess it's possible, I don't know, mate. There's no evidence of it, but that doesn't mean it couldn't happen."

"I think… I think I'm the proof," Sirius said, his voice dropping to a whisper.

"What?" James gasped.

"I think I'm from a parallel universe," Sirius explained, sitting down next to James. "Or this is the parallel universe, I don't know, I'm not sure if one is more real than another, but this is not the place that I lived in."

"How so?" James questioned. To Sirius' relief, he sounded more curious than disbelieving. "I mean, what are the differences?"

"There was this wizard –"

"Voldemort."

"Yeah, he was pretty evil, bout as bad as it gets," Sirius explained. "He fueled all the pure blood mania, and he killed anyone who opposed him. The Death Eaters were his supporters, the nearest and dearest who completely believed that muggles and muggleborns were scum and deserved to die. Regulus was one of them. We were a part of an order that fought against them, you me, Remus, Lily. Voldemort, he… for some reason he got into his head that you and Lily, and Harry, were the biggest threat to his power. He went after you and he…"

"He killed us," James finished, when Sirius could no longer go on with his story.

"Yeah," Sirius confirmed. "But Harry survived. He lived, and he brought down Voldemort, for a time at least. But now he's back and Harry's fighting him again."

"How old is he now?" James asked. "In your world. How old was he when we died?"

"He's almost sixteen," Sirius answered, the first bit of the information easier to share than the second. "The night you died… it was tonight."

"Oh my god…"

"Hey, James, he's fine," Sirius reassured his best friend. "He turned out great, I mean you would be so proud of him."

"James?" Lily poked her head around the doorway, baby Harry perched on her hip, happily stuffing his fist in his mouth. "If we don't go soon, it'll be too late."

"Yeah, of course, let's go," James said, shaking his head as if to clear away the cobwebs of the conversation he had just been having, and he stood up, reaching out for his son. "You're still coming, right?"

"Of course he is," Lily said, smiling. "We can't have Halloween without our son's godfather, especially since he bought Harry's costume."

For the first time, Sirius looked closely at Harry's outfit. He had on sky blue robes, with navy pants underneath, and a shirt that had large navy and sky blue checkers on it. Emblazoned on the chest of the robes were too small, overlapping Ts. James picked up a little broomstick as well, the small toy one Sirius had given Harry for his birthday.

"Well I do have excellent taste in costumes," Sirius smiled. "Are you sure it's okay to take him out in that around muggles though?"

"Yeah, yeah, the costume is charmed to look like some muggle football team to muggles," James answered, waving nonchalantly.

"Right, makes sense," Sirius nodded.

"Which team?" Remus asked, entering the kitchen with a smile.

"Er, West Ham, I think," James answered with a shrug. As a Pureblood wizard, muggle football teams meant next to nothing to him. "Does it matter?"

"Well they could have at least picked a decent team, like Villa," Remus joked, and Sirius rolled his eyes.

"Boys, no fighting," Lily interrupted, before Sirius could answer.

They all followed Lily out of the house and proceeded down the street. With each house, the group walked up to the door and rapped on the wood, Harry squealing with delight. Some of the houses had Halloween decorations that made noises when you got close or lit up, and a few people even hid in their own bushes and jumped out to surprise the visitors. Each time, Harry squealed and laughed, a light, happy sound that made Sirius' heart soar.

As they walked through Godric's Hollow, they chatted about little things in their lives. Lily was thinking about going back to work, and thought it might be good for James to do the same thing. They were rich enough not to, to be sure, but neither one of them were suited to sitting at home endlessly. James, on the other hand, protested that they had plenty of time for work in the future, and for now he wanted to focus on having more children. He wanted Harry to have brothers and sisters, lots of them, and he wanted them to be close in age. Lily was less sure about it. It made sense, given their background – as an only child, James had always craved siblings, but Lily's experience with Petunia had left her wary of the idea. Remus said he had been offered a job through St Mungo's. They wanted him to work in counseling patients who could not be fully healed from their illnesses and injuries. It was a dream come true for him, to have an employer who knew of his condition and embrace it, seeing in it the possibility to help other people. Sirius remained quiet for most of the conversation, congratulating the others when it was called for, and adding suggestions or advice, but he offered no details of his own life.

"Sirius, do you want to hold Harry for a bit?" Lily offered as they began to walk back to their house.

"Oh, I don't know…" Sirius blanched, wanting to decline. He had had precious few opportunities to hold his Harry when he was a baby, and it had been so long since then. "I don't want to hurt him."

"Oh go on, you'll be fine, he's tougher than the looks," James said, nodding to encourage Sirius.

Lily held the infant out, and Sirius cautiously took him into his arms, settling him against his chest. Harry yawned and nuzzled his head into Sirius' neck, and suddenly Sirius could no longer hold back his tears. He rubbed his free hand around Harry's back, and the infant closed his eyes sleepily.

"Sirius, are you alright, mate?" James asked, looking at him with concern.

"Yeah, I just…" he looked up at James, their eyes meeting, and an understanding seemed to pass between them.

That night, having his best friends back and seeing what life could have been like for all of them if Voldemort had not destroyed everything, it had been a dream. He wanted so badly to stay, to forget his other life, his time in Azkaban and live in this world, where his best friends would get to see their kid grow up, and he would have a life with the man he'd always wanted. But it also reminded him of everything that had happened in the other world, and had reminded him that while he might have lost a lot in his reality, so had Harry, and Harry needed him. He couldn't let his godson lose someone else. It was his duty, as Harry's godfather, to look out for him. He had failed at that for 12 years, but he couldn't do it anymore. His entire world was Harry. This Harry would be fine. Part of Sirius craved seeing this Harry grow up, but he knew in his heart that it was not what he was meant for.

"I have to get back to my Harry. He's alone, he needs me. I can't leave him, not again, it would crush him. And I have to protect him. James, I'm sorry, but I have to get back to my world."