In This Heart Of Mine (Sirius Black X Fem Reader)
Sirius's time in Azkaban had been awful. It was something he wouldn't wish on anyone, not even his worst enemies. The Dementors always trying to force him to relive his worse memories, although they failed for various reasons. Namely him focusing on his innocence, for the crime he'd been accused off, and he often spent time in his animagus form. Yet even that didn't stop him from remembering those he had lost during the war, both to death and those whom turned away because of the crime he had supposedly committed. The betrayal of Peter Pettigrew, someone he once mistakenly believed was a friend.
James and Lilly, both hailed as heroes for their sacrifice that went on to end the war. Friends whom had been murdered for standing against Voldemort and his black clad followers. The Longbottom's had been tortured into insanity, not long after Voldemort's fall. Yet the one to hurt Sirius the most, was the loss of his (Y/N). She'd been taken from him during one of the many battles, all of it had happened so quickly and ripped his heart to shreds.
Flashback
It had been the height of the war, 1980. Things had taken a dark turn with members of the order being slaughtered left and right. The Prewett brothers had been murdered, Marlene McKinnon and her entire family had been wiped out by the Death Eaters as had several others. At every scene the dark mark was cast, as if to strike more fear into those whom were already terrified. Distrust also ran riot within the Order, especially when it become clear there was a traitor in their midst, someone feeding Voldemort information, that allowed the onslaught to happen. Long time friends and family distrusting each other, because of suspicion and fear.
(Y/N) had been sent out on an assignment, Dumbledore had personally sent her on it, with hope valuable information would be found. He'd chosen her for her metamorphic abilities, allowing her to be anyone if she so willed it. Only a few knew of her mission to find information, by infuriating the Death Eater ranks. (Y/N) had been close to Sirius and the Marauders since their school days, always pulling a prank or tripping over something. No one knew of her assignment, until days after she'd been sent, her disappearance noticeable.
Lily had been the first to speak up over (Y/N)'s disappearance, Sirius admitting he'd noticed but hadn't voice his concerns, due to hoping she'd return sooner or later. Every night he hoped to see her at the dinner table, just as he found himself preying (Y/N) was okay, even when he didn't know the nature of her assignment. Dumbledore had personally answered the question, when Lily had asked, although he'd not told her at dinner, instead inviting her, James, Remus and Sirius his and Alastor Moody's shared office. Moody being the only other to know of (Y/N)'s assignment to find information and if possible the identity of the traitor in their mists.
Weeks had gone by and no word was heard from (Y/N), letters sent and all form of communication had gone unanswered. The last time (Y/N) had responded to give the information on an impending attack at a muggle park, in the dead of night. It was supposed to be an attack against muggles, to strike far more fear into them, to use them as an example of the cruelty Death Eaters were capable of. So the members of the Order had arrived to prevent it, meeting the black clad Voldemort followers there, they being lead by the twisted Bellatrix of all people, Lucius Malfoy, Rodolphus Lestrange and Evan Roiser all present. In the clutches of Bellatrix was (Y/N), far worse off than before, wandless as Bellatrix held (Y/N) wand as if it were a trophy of triumph.
"Looks like our mole was right" spoke Lucius, his voice barely above a whisper as he stood next to his deranged sister in law. Her wicked smile spreading as she held on to (Y/N)'s tangled black locks, pulling harshly to force her to look at those, whom she was friends with, whom she fought side by side with on so many occasions before hand. Lucius knew the order Voldemort had given, (Y/N) had refused to give him anything, blocked his attempts to read her mind, even when tortured. Instead she had stood in defiance against him, stayed silence and even attempted to to hide her pain.
"Avada Kedavra" yelled Bellatrix, her wand pointing at the younger metamorphic witch knelt in front of her. Hearing her cousin Sirius scream out when the flash of green light surrounded (Y/N), Remus had grabbed hold of Sirius before he could run head first into the jaws of doom. Holding his old friend when he screamed out (Y/N)'s name, calling for her to answer as his blue eyes turned glassy. As if by design the death eaters left, it being clear the planned attack and be redesigned into an execution, meant to show the members of the Order, there would be no mercy regardless of their blood.
Sirius soon broke free, running to the lifeless body of (Y/N), pulling her into his lap. Begging her to wake up and come back to him. Even when he knew she was gone, he still begged her to wake up. Sirius had never told anyone of his love for the metamorphic witch, nor about his desire to marry. He'd been to afraid she'd reject him if he told her, too afraid he'd become everything he feared. He knew for sure his family would banish him for sure, after all (Y/N) was a half blood. Yet still he wanted nothing more than to tell her the truth, for her to wake up and tell him the answer to his wild question and request.
Despite that Sirius knew it was impossible. His deranged cousin had killed her without even blinking. (Y/N) hadn't even been able to pass on the information she had collected, having been betrayed and captured before she could. She being destined to be another name on the seemingly endless of causalities of the war.
"Wake up (Y/N), Wake up. I love you. Please wake up" whispered Sirius as Remus sat besides him, a hand on his shoulder. A silent promise being made, he'd write a letter to James and Lily to inform them, the two have since gone into hiding, from the threat of the dark lord.
End of Flashback
The night Remus found him in the caves near Hogwarts twelve almost thirteen long years later. He'd given something to the former prisoner of Azkaban. The photo of (Y/N), Sirius had kept on him everyday since leaving school, the photo he'd promised to keep with him ever since he lost her. Deep down Remus knew (Y/N) would have fought for Sirius had she lived, she would have tried her hardest to convince so many of the truth he now knew. She would have fought to prove Sirius's innocence no matter what.
"In this heart of mine, we've live for a lifetime (Y/N)" whispered Sirius when Remus left, his blue eyes focusing on the ageless (Y/N) pictured, her sweet grin. "Lily and James are with you always. One day I'll see you all again" muttered the Marauder, making a silent vow of revenge against the one whom had betrayed so many. And to protect his god son, the boy with the weight of the world on his shoulders. Harry.