Follow their relationship from 1981 to the end of OoPT plus epilogue. Warning in advance - my interpretation involves a 17/30 y/o relationship. And obviously I don't own anything. Enjoy!
The news was spreading through the magical community like wildfire. Lord Voldermort was defeated. But the joy was tinged with sorrow, because so much had been lost for this victory; so many good wizards and witches, so many innocent muggles caught in the crossfire.
And, it was later discovered, brilliant wizard-and-witch couple James and Lily Potter. Their one-year-old son Harry had somehow survived – no-one knew what kind of powers a baby would have that would defeat Voldermort where his parents had failed – and had been hidden by Dumbledore.
But for many, still more bad news was to come. It was discovered that none other than James's school mate, best friend and best man at his wedding, Sirius Black, ad been the one to betray the couple to Voldermort, revealing their secret whereabouts. Not only that, but when another member of their school group, Peter Pettigrew, had confronted Sirius about it, Sirius had killed Peter as well. The man didn't care who got hurt in his devotion to Voldermort.
Or so it seemed. Ted and Andromeda Tonks, for one, found it difficult to believe that Sirius was capable of betraying James and Lily. They went so far back; James had let Sirius stay with him after Sirius had left his family when the situation had become unbearable. Andromeda and Sirius were cousins, and she knew just how unbearable the Black house could be to live in. She couldn't imagine Sirius going back to the side he had so hated all his life. Perhaps he had been under an Imperius curse? Certainly, it seemed so unfathomable that he could have betrayed his best friend of his own free will.
But there was no answering that question now. James and Peter were dead, and Sirius was in Azkaban. Which only left...
"Poor Remus," Ted said, sensing his wife's thoughts. Andromeda nodded, thinking of the fourth in the little band that had caused such hijacks at Hogwarts School of Witchcraft and Wizardry for seven years. Remus Lupin, who had been made Prefect in an attempt to bring James and Sirius's boisterous way under control (though he had failed miserably). Remus Lupin, who had suffered as a werewolf for most of his life but found friends in James and Sirius who cared more about his loyalty as a friend than any non-human qualities that he might have.
Andromeda nodded. Remus had lost his three best and most supportive friends in one go – James and Peter to Sirius, and Sirius knowing that he was a traitor of the worst kind. "He must be so lonely," she said sadly, her heart going out to a young man whose only bright spot in a lonely life were three young men who he no longer had. "We should have him over," she suggested. It had to do some good for him to be with people who recognised that being a werewolf didn't automatically mean he was an monstrous being. At least, it couldn't do any harm.
"I agree," Ted said.
"I blame myself," Lupin said with resigned sorrow. He had thought about it over and over, wishing he had seen the signs – but what signs? There were no more devoted pals that Sirius and James, or so he had thought. Lupin himself had often felt a little left out of that special something that the two brilliant, handsome men shared. Had it all been an act? Or had Sirius at some point decided that there was more to be gained from turning to the dark side?
"You weren't to know," Andromeda said kindly. "We all thought they were as close as two people could be. Do you think there's a possibility he was under an Imperius curse?" she asked.
Lupin shook his head. There was always the possibility, of course, but the thing with the Imperius curse was that there were often things you noticed when a person wasn't acting quite like they should. He had searched his brains and could think of nothing to suggest Sirius had been under the Imperius curse. So the only alternative was that he had put up a brilliant act after he had changed sides and continued to behave as if he was James and Lily's best friend and closest confidante.
"I'm sorry," Andromeda, expressing her sorrow not only for Lupin's loss, but for all of theirs.
Lupin smiled wanly. There was no point in wasting a rare opportunity to be with people who didn't judge and fear him by feeling sorry for himself. "At least it's over now," he said. "Imagine, Dromeda, people will be able to go about their daily lives without having to worry about being tortured or imprisoned or their loved ones taken from them. Parents will be able to raise their children as they see fit. Speaking of which – I hear you have quite the precocious daughter."
It was exactly the right note to hit. Andromeda smiled with love and pride to think of her eight-year-old daughter Nymphodora. "She's very talented," she said. "A little bit rambunctious at times – doesn't like following the rules – or, rather, only follows the rules when they exactly suit what she wanted anyway. And she's showing signs of being a very talented metamophmagus – can you imagine how much trouble she'll get into when no-one can work out who she is?" Lupin laughed at that, thinking how much James and Sirius would have loved to have Nymphodora in their little gang. Although Nymphodora was only seven years older than little Harry – she would have been more of a daughter to them than a contemporary.
As if knowing she was being talked about, the eight-year-old came through the door, tripping over a step that she must have known by heart was there by now. Lupin smiled indulgently at her clumsiness. He took in her violet hair that was a sure sign of a metamophmagus and smiled even more broadly. She definitely had a precocious look about her, and if she was anything like her parents – intelligent, loyal, defiant – than she would be one hell of a witch.
"Nymphodora," Andromeda said. "Come and meet Remus Lupin. He's a friend of mine. And was a friend of James Potters, too."
Nymphodora's eyes went wide with interest. Anyone who could claim a solid connection to the Potters and Sirius Black was worth a good conversation, although many felt that Lupin's less-than-desirable traits excluded him from that category. Really?" she asked. "And Harry, too?"
"I met him a few times," Lupin said. "Not many people know where he is now – and I'm not one of them."
Nymphodora took the information in. Remus Lupin seemed very sad – but a lot of people were sad these days. Despite that, there was something that drew her to him. After just a few seconds, she was fascinated by him and felt the urge to sit on his lap. He was younger than her mum and dad, although still much older than her.
Lupin was impressed by this eight-year-old who was far more intelligent than her years would suggest – although she possessed a clumsiness of someone half her age. For some reason, that just made her appear more endearing. There would be something a little insufferable about a beautiful, intelligent young woman without flaws; her clumsiness only made her human.
"Thankyou for having me over, Dromeda," Lupin said as he was leaving."It's been a while since I socialised."
Andromeda nodded, silently understanding. Humans distrusted him for being a werewolf, and werewolves distrusted him for wanting to live in the civilised fashion of humans; both races felt he was betraying the other and as such, he was welcome at very few houses of either. "Come over whenever you feel like it," she said sincerely. "I mean it. We love having you around and it will do Nymphodora the world of good to have people around her who remember what it was like when the Dark Lord reined."
Lupin nodded, appreciating Andromeda friendship and hospitality deeply in this world where there was still so much distrust being different races and within races themselves. "I will," he said.