Disclaimer: Characters owned by J K Rowling, obviously. The Mirror, imagined/owned by myself.

Summary: For everything in this universe, there is an opposite. Yin and Yang, Fire and Water, Light and Dark. So, for the Mirror of Erised, that shows you the deepest and most desperate desires of your heart, surely there must be an opposite? Beware, for when you look into the Mirror of Cosmaruri, you will see the darkest, most terrible nightmares – you will see whatever you fear the most.

WARNING! This story will contain SLASH, as in two blokes, in love. You have been warned.

The Mirror of Cosmaruri

Athazagoraphobia

"And then she tells me that our son, our SON, will have EYES THE COLOUR OF DEATH!" James Potter fell silent, and sat down heavily on his four poster bed as though all the strength had drained out of him. He sighed, head in trembling hands, hiding suspiciously shiny eyes from the view of his two best friends. Sirius glanced over at Remus, and could see his own shock and surprise mirrored in the werewolf's gaze. There was a pause, an awkward moment of silence, where Remus and Sirius hardly dared breathe. Eventually, Remus stood up, moving almost silently. He gave Sirius a quick hug, murmuring just loud enough for his boyfriend's canine-enhanced ears to hear the slight whisper of encouragement.

"Sirius – he needs you. A brother. Just… Go with your instincts, and you'll find the words. Okay?" He embraced Sirius gently, a quick affectionate squeeze, tears burning in his eyes. Sirius inhaled deeply, the wild, woodsy scent of his soul-mate calming him instantly. Then, he was alone, hovering nervously by James' bed. He cleared his throat slightly, and James looked up. His eyes were swollen and red, tears dripping from the end of his nose, smudging across his glasses. His bottom lip was quivering like that of a terrified child; but his gaze was unblinking and strong. Sirius reached out a tentative hand, and in an instant, he knew what to say.

"Budge over then, Jim. I'm shattered." James grinned half-heartedly, the smile not quite reaching his eyes. With a sigh of agreement, he flopped back onto his bead, Sirius plopping down next to him. They both reached up, hands behind their heads, knees slightly bent, gazing at the frayed canopy. James let out another sigh, this one soul-deep, his breath hitching. They lay there in silence, Sirius counting the frayed golden stitched in the red velvet overhead. His vision was just beginning to blur, when James mumbled something indecipherable. Sirius answered in a similar fashion, with a confused, dog-like whine. James smiled softly. "I said, I'm on forty seven, mutt." Sirius laughed; a cross between a puppy's bark and a bicycle pump.

"Fifty three! Bite me, antler-boy!" James laughed too, and while there was a slightly desperate edge to it, it was definitely a laugh. Smiling, Sirius rolled onto his side, propped up on an elbow, chin on his hand. The other hand trailed his wand lazily through the air, conjuring sparkles of light, violet, crimson and gold. James lay there for a few moments, his breathing gradually slowing, evening out. He could hear Sirius whistling some random tune by his latest Muggle obsession, and there was an icy draught playing with his hair. He frowned slightly, before rolling over to face his friend, his brother, eyes snapping open.

Sirius let out one last mournful whistle, his wand dropping soundlessly to the bedspread. He cleared his throat and dropped his eyes to his hand, picking at the duvet, unable to hold James' gaze as he began to speak. "So… S…So how… Are you feeling okay? I mean, obviously you aren't, but… Look, James, I… It isn't gonna happen you know. Not the way she saw it. I… I won't let that happen, not to you, because you're a good man, a good friend! You're brave, and loyal and honest and true, and… I won't let it end the way she saw it, I won't-"

"How would you have it end, then?" James interrupted, sitting up cross legged on the bed. Sirius sat up too, spluttering in confusion. James took off his glasses, massaging his eyes tiredly with the heels of his hands. He continued speaking, his voice suddenly far too loud, far too heavy in the room. "How would you have it end, Sirius? Me, dying an old, old, man, older than Dumbledore? So old and deranged that I can't even piss by myself? Surrounded by my friends and my family?" He paused, and Sirius gaped at him, aghast. He had never heard James speak with such bitterness. "We run around thinking we're immortal. Laughing in the face of death because we think we're invincible, like no one could ever touch us. But… Okay. So we might surpass the danger. We might actually survive. But what happens then? Would you have me end up old and alone, sitting around and waiting to die? Waiting to join my darling wife. My wife, or my kids, or… Or my friends. Would you have me die alone, waiting to join everyone that died before me? I… I couldn't do that, Sirius. I couldn't watch you all die, I couldn't… I can't grow old without you!"

Sirius blinked. And then he understood. "Oh James. You… The reason you're so upset… You think… It would be… better?" James let out a groan of frustration, and both boys flopped back onto their backs. "I just think that… Well… What's so bad about it? To die fighting, defending everything you love? Isn't that how you'd want to die? In the place of someone you love?" Sirius frowned. James continued, the words spilling out, causing goosebumps to break out across the back of Sirius' neck, goosebumps that had nothing to do with the wintry cold. "Think about it, Sirius. Imagine… Remus. If… If Remus, YOUR Remus was in danger, if he was going to DIE… Wouldn't you do it instead? Wouldn't you sacrifice yourself for him? Or… Or for me? Or even Reg-"

"No." The word was cold and icy in his mouth. It tasted like dirt and tears. Sirius stood up, his face crumpled oddly, as though he had been smashed and glued back together. "James. You… You don't understand. You're… I'm not you, James! I can see it y'know. You, dying in a… a blaze of glory, fighting 'til the end. Ever the Gryffindor. But… I'm not like that. I… You… You can't expect me to… YOU CAN'T ASK THIS OF ME!" Sirius leapt to his feet, and stormed from the room, grey eyes glinting with desperation and fear.

James blinked at the slowly closing door, and sighed. "So… Y'think this is a sign, Jamie-boy? A sign of things to come? 'Cos here you are, alone again. You ran out on the love of your life, and now your best mate has run out on you." He flopped one arm over his face, and soon all that could be heard was the sound of his breathing, deep and uneven, as James tossed and turned, ensnared in fitful sleep.

Sirius couldn't stop running. He stumbled through the Gryffindor Tower, through the Portrait Hole, down the main staircase, and across the lawn. Eventually, he staggered into the cobble-stoned courtyard, and flopped down on a snow-covered stone bench, ignoring the instant freezing wetness that seeped through the seat of his trousers. He leant bonelessly against the archway, his head bowed. His breathing was heavy and ragged, and he could hardly think past the cold that was crushing his chest, and the burning stitch in his side. All he could see was James' earnest, tearstained face, asking again and again, If Remus, YOUR Remus was in danger, if he was going to DIE… Wouldn't you do it instead? Wouldn't you sacrifice yourself for him? Or… Or for me? Would you die for me? Would you sacrifice yourself for me? Would you die for me, for him, would I? Would I die for him? For Remus? For Peter? For my friends? Or… For… For… Regulus.

He had scarcely just thought of his brother, when a familiar voice broke through his desperate thoughts. "Well well well. Look what we have here! A big, brave Lion. Without his pride. Finally seen through you, have they, brother?" Sirius' head snapped up, and he glared at his younger brother. "Regulus." He spat, a mockery of politeness. Outwardly, he was the picture of hostility. Inside, he was shaking. The resemblance was uncanny. When Sirius had looked into the Mirror… He had seen himself, grown up and Dark. His eyes had been hard and cold, cruel and unforgiving as steel. The very same eyes as the ones that presently resided in his baby brother's face. Dear Merlin, Sirius thought, shocked to the core. What… What have I let him become?! Some of his pain must have shown on his face, because Regulus took a step backwards, his previously sneering face a blank mask, as white and emotionless as the frozen lake spread across the world behind him.

"Something wrong, brother dearest?" Sneered the youngest son of Orion and Walburga Black. Sirius growled and leapt to his feet, leaving all previous lethargy behind him in the snow. Regulus smirked, his eyes cold and calculating. "I'll take that as a yes, shall I? What's wrong? Nothing too serious I hope. Wait, don't tell me… Maybe your stupid Blood Traitor friend went and fell off his broomstick, and did the world a favour? Or… Or maybe its something to do with your precious little werewolf? Tell me, has it finally gone rabid? Or maybe he got you too, maybe you're a monster t-"

Sirius couldn't help it. That poisonous mouth, looking so much like his own, spewing filth, hateful lies, about the man he loved – It was too much. He felt his resolve snap, and his fist collided with Regulus' perfect square jaw, sending him sprawling onto his backside in the snow. Regulus instantly scrambled to his feet, flushing with shock, and injured pride. His eyes weren't cold anymore, but burning, boiling, wrathful anger. "DON'T YOU TOUCH ME, DON'T YOU DARE TOUCH ME, WITH YOUR FILTHY, TREACHEROUS HANDS!"

Sirius took a step backwards, the words raining over him like burning ashes over Pompeii. He cleared his throat, eyeing Regulus' already purpling jaw guiltily. "Reggie, I-"

"DON'T call me that! You haven't got the right! You don't deserve the right to speak my name, filthy, miserable traitor! You're pathetic, resorting to Muggle violence! You're as bad as a Mudblood-"

"Shut up! Don't call them that! Some of the Muggle Borns are twice the wizard you'll ever be! Just because they're different to you, just because you don't understand-"

"How dare you speak to me that way! How dare you speak favourably of those inferior FILTH! How can you even bear to look at them? To be near them? They STINK of their dirty blood, they couldn't be decent wizards if their miserable little lives depended on it, and you know as well as I that-"

Here, Sirius could bear it no longer. He moved forwards again, clapping slowly, his face flushed with righteous anger. Regulus fell silent, frowning, confused. "Congratulations, Reggie!" Sirius spat, sounding just as hateful as Regulus a moment before. "Congratulations, brother. Congratulations, LORD BLACK. Mother and Father must be SO PROUD of you! Spouting off their little speeches – tell me, are they easy to remember, or do you have to rehearse?!" Regulus snarled, and raised his wand, pressing it into the soft hollow beneath Sirius' throat, backing him into the damp stone wall.

"You'd better watch your tongue, brother. It is not wise to speak ill of the Noble and Most Ancient House of Black. There are some who would be most… displeased to hear such little speeches, and then… Then, Sirius, even you're little pet wolf won't be able to save you!" Sirius snarled, but didn't move. An angry Regulus was a dangerous one. And… These days, who knows? Maybe his brother would actually slit his throat, and leave him to die. Regulus certainly hated him enough.

Sirius didn't let his uncertainty filter through to his face, however. He laughed recklessly, the laughter erupting into a roar of anger before it even left his throat. "He's not my pet! He's my- My friend. N…Not that you'd understand anything about that-" Regulus jabbed his wand further into Sirius' throat, making him cough and fall silent. His eyes were glinting, silver and curious.

"Your… friend? Really. Is that so? Tell me, Sirius. Do you think that I'm stupid?! Do you think, that after fifteen MISERABLE years on this planet, that it is even slightly possible that I do actually possess even the slightest amount of common sense? Because I'm not stupid. In fact, I'd say I was a damn sight less stupid than YOU, brother. It's so obvious. SO obvious. But I had no proof, see. And, I don't think you even knew. But… He's your… friend? You didn't sound too sure. Do you want to change your answer, Sirius?" Sirius was suddenly and painfully aware of the ice cold water seeping through the back of his robes, and the cold winter sunshine glaring and bright, forming an almost perfect halo around his brother. He glanced away, unable to hold his brother's searching gaze.

"I… I don't have to explain myself to you!" He shoved his brother off him, and stumbled backwards, wand aimed at his brother's still smirking face. Regulus just laughed nastily, and walked forwards slowly, a panther stalking his prey. "Ah… So it was a lie."

Sirius snarled, and leapt forwards, sending both boys smashing to the ground. "IM NOT A LIAR!" He roared, grabbing the front of Regulus' robes, and smashing his head against the ground. Regulus blinked, dazed, but continued to laugh. He laughed, and laughed, until it turned into a hacking cough, and he rolled over, slipping from Sirius' suddenly slack grasp. He coughed and coughed, unaware of a tentative hand on his back, his brother's suddenly panicky voice at his ear. "Reggie? Reggie, are… Reggie?!" Regulus snarled and spat blood onto the cobblestones, thick and ruby red, garish in the daylight. He staggered to his feet, one hand pressed to his chest, the other holding his wand. His hand was shaking violently, but his aim stayed true. Sirius stood very still, hands raised in a mockery of a surrender. "Regulus, I think you should go to the Hospital Wing, you need-"

"SHUT UP!" Regulus even managed to look intimidating with strings of bloody saliva hanging from his mouth. "WHO ARE YOU TO TELL ME WHAT I NEED?! You're the one that's sick!" Sirius went white with anger, and involuntarily clenched his fists. He turned away, and started towards the castle – but Regulus wasn't finished yet. The curse that took him by surprise wasn't one he'd heard of before; probably another sick Slytherin invention. It sent him sprawling across stone and grass, until his was slammed up against the castle wall, his spine popping, and the still semi-healed wound on his shoulder splitting open in a burst of pain. Regulus stumbled over, his breathing shallow and wet, like his was underwater. He spat a mouthful of blood at Sirius' feet, and grinned at him, his teeth and gums stained scarlet. "Well. You know, I think someone's trying to hide something… You really shouldn't bother, Sirius. I can read you like a book. You never could hide anything from me. So don't even try." He laughed, eyes shining crazily, reminding Sirius of his mother. Regulus leaned closer, and as his brother whispered in his ear, Sirius could almost smell it, the smell of Grimmauld. Dark magic and blood. Cobwebs, mustiness. Secrets in dark corners. "Besides, this will hurt far less, if you don't fight it. Don't fight it, Sirius. Trust me, and don't fight it." Sirius opened his mouth to protest, but before he could even make a sound, Regulus had raised his wand.

The curse was silent, and faster than lighting. Sirius couldn't breathe, couldn't see, the world was spinning and bright, like he was flying weightless, above the clouds. Then they started. His memories were spinning around him, a bright circus of lights and sound. He could hear snatches of voices on the wind - his mother, shrieking, the sound of James cheering during Quidditch practice... Baby Regulus, laughing at nothing, calling for his older brother... Remus… The sound of Remus' breathing as he slept… Something deep inside of Sirius gave a pang of longing, and somewhere far away he could hear Regulus laughing. "Just friends, was it brother?!"

Yeah. Just friends. I don't know who you think I am… There's no way you could lie to me – to ME! I'm your brother! I know you!

I…

I know that when you're happy, your smile lights up the room.

And… that when you laugh, its impossible for me not to join in.

And when you're truly, utterly furious you turn an enviable shade of scarlet, and your hands start shaking...

I know that when you're afraid your face goes white, and you blink too fast.

I know that you act like you're never embarrassed… but if you're ashamed you always laugh just slightly too loud, and your smile is just that bit too bright.

I know that when you think of home, your eyes go dark, and you bite your lip.

I know that you never lie. Sure, you twist the truth a bit… But never LIE. Which is why I could tell, why I could see right through you. Because you wouldn't look me in the eye. Your voice sounded wrong, sort of thin, like you were inwardly cursing yourself. Like you didn't want to be speaking at all.

Brother, I know you. I knew you were hiding something from me, but…

I don't know why.

Legilimens.

The echo of the spell reverberated around Sirius head, making him close his eyes in pain, as his little brother fell into his memories, still chuckling. And there he was, straightening up, fixing Sirius with an omniscient stare. "Did you like my little spell, brother? Any fool can be a Legilimens, but it takes real skill to find the right memory first. I knew you were hiding something from me… And I figured it out, almost instantly. I'm not stupid, you know. But… I can't help but wonder… Why can't you look at me? Why, why do I make your face go white, like you've seem a Grim laughing from behind my eyes? What do see when you look at me, Sirius? What is that you're afraid of?"

Sirius shivered, panic rising as he noticed their surroundings. Calm down, Sirius! It's just your mind, just the inside of your own head. Nothing can hurt you here, it can't reach you here, it can't, it really can't… Can it?

The walls were fading out of the shadows, tall, grey stone, damp and dark, as though splattered with congealing blood. And there, looming towards him, brought forth from his mind by Regulus' words.

The Mirror. Sirius let out a bloodcurdling scream, and fell to his knees, hands pressed over his ears, eyes scrunched shut. "NO! No, you aren't here, I'm not here, it can't be, can't be… Just my mind, this is just my mind, YOU CAN'T KILL ME HERE! Please, don't kill me here, don't let me die here, don't… Don't… Please…"

Regulus frowned, looking around in confusion and exasperation, as his brother disappeared into some corner of his mind, slipping away, blanketing himself in mist, shielding himself from his memories. "Sirius? Where…?" He didn't even have time to ask the question, before the sky opened up, and Sirius fell through, landing at his feet with a crunch. Regulus let out a yelp of surprise, gaping in shock as memory-Sirius staggered to his feet, calling for his friends. He stumbled around, like a crippled dog, before crumpling to the floor, spitting blood everywhere. "Sirius!" Regulus couldn't quite manage to bite his tongue in time to capture the exclamation of concern as he watched his brother discover the body of the Slytherin, hanging limply from the ceiling. "Sirius…" He placed a hand on his brother's shoulder, and bowed his head, as the Slytherin was buried, with dignity. Such… such respect. Would… Would you have done the same? If it was a Gryffindor hanging there? A flicker of shame twisted uncomfortably in the pit of his stomach, but he brushed it aside, concern mounting, as Sirius reached up, and pulled the dustsheet to the floor.

A mirror.

Tall and menacing, radiating evil. Regulus stepped back, licking his lips nervously, watching as Sirius began to moan and cry, clawing at his face, and, and – the pickaxe? "Sirius? What the hell are you doing?! P…Put that down, what are you-!"

Blood, his brother's blood, was spraying across Regulus' face, splattering the mirror with a glaze of red, as though it were ashamed.

"SIRIUS! I… I've had enough now! What is this place? Where are we? Sirius, I'm speaking to you! What memory is this?! What happens here?! Sirius? Sirius!" But his brother wasn't listening, he was laughing hysterically, staring with wild, terrified eyes at his own reflection. "Stop looking at it! SIRIUS, STOP-"

That… That wasn't his brother's reflection.

That was… That's me! But… But it can't be! I'm just… Just a spectator, I can't… How is that me! How can that be me! I… what is this place?!

He stepped backwards, transfixed, his eyes unblinking, never leaving the mirror's surface. His mouth fell open in a silent scream of fear, as he saw the surface of the glass ripple, and change, and change him into something, into someone else.

Sirius.

His older brother was staring back at him, his eyes full of hatred, full of disgust.

Regulus couldn't breathe. A hellish red-black fog had invaded his mind, making it difficult to think. He didn't hear his brother screaming that he hated him. He didn't hear his brother, his brother telling him that he should never have been born. That Sirius wished he would just die.

He didn't need to.

The image of his brothers hateful eyes branded itself into Regulus' mind like a red hot poker, and all he could do was watch, shivering in horror and fear as his stupid, brave, idiotic, wonderful, Gryffindor brother turned away from it all.

From the Blacks.

From the Slytherin's.

From Regulus.

Leaving the younger Slytherin alone, so alone, alone and forgotten, left to grow old, and make mistakes and die alone.

Because who could ever replace the gaping wound gouged deep in his heart - where his brother used to be?

Author's Note:

Athazagoraphobia – A fear of being forgotten.

Okay, first off: I am so so so so so so sorry this took so long! It's been like… months!

Anyway, I hope you liked the chapter – I know it was a bit different, but I was getting tired of the same old "discovered a random room" kind of plotline that seemed to be taking over, and so I decided to have a bit of a change…

Anyway, reviews would be greatly appreciated!

Thanks to Bottlebrush for constant reviews – it really does mean a lot to know that people appreciate my work.

Next Chapter: The one we've all been waiting for – The Marauders have had enough, and Albus Dumbledore meets the Mirror of Cosmaruri. Who will win this time?