Snape had heard of the mirrors great powers. The way men slowly withered away, entranced by its tales of perfection, of the perfect life that more often than not remained unattainable, those who sought after it with such a passion that the life they led outside of fantasy could never compare, and they died sad, the happiness they had once felt being mere teens with big dreams and no one to bring them back down to Earth and tell them it would never happen.
Snape was almost certain of what he would see, his beautiful Lily by his side instead of James'. But he knew it could never happen. He'd driven her away and instead of doing what a true man would've and fought for the woman he loved, he'd sulked and brooded, letting his hatred of the man who'd taken her overtake the hatred of the man who'd let her go, because no mixture of ingredients that could possibly save himself from the pain of hating himself. Because despite everything, he knew it was true. He'd let her go.
Dumbledore told him of the boy who'd stood in front of the mirror and saw only the family he'd never had. And for a while, his hatred of the Potter boy broke. Because that too was his fault. Maybe if he'd stepped up, James wouldn't have been the father of Lily's child but he himself. But eventually he went back to despising the boy because instead of Lily's child being his, he was James. And surely the child of James Potter could be no good.
From the first time he heard of the mirror he knew immediately what he would . His sweet Lily. And why wouldn't he? His life had been spent dwelling over what could have, what should have been. The family he and Lily would've raised. The soft smiles they'd share. A very wise old man once said 'love your best friend, for there is no one will know or love you more'. Lily had been more than just a best friend- she'd been his only friend.
On the worst days, on the anniversary of Lily's death or on the anniversary of the day he'd lost her *February 11*, he'd dream of what could've been. He'd see things. Lily's beautiful hair framing those eyes, those goddamn eyes that symbolised everything about Lily that lived on in Harry, her face lighting up and her grasp on his hand tightening as their little one took his first steps. He and Lily taking their son into Ollivanders and watching wand after wand until those beautiful lights erupted from the end of a wand and Lily smiling at the little 'd cheer on their son as he got sorted, into Gryffindor -he was sure of that much. Their son would've been more Lily than him-. But none of that could happen and every time, he'd wake up in his bed sweating and shaken and he wouldn't get back to sleep until he either took a sleeping potion of just got too tired to keep his eyes open.
After a while, the need to see her again overwhelmed the warnings that came with the mirror, and the need to truly know exactly what he would find in the mirror became overwhelming, and one dark night the potions master made his way from the dungeons and up to the Charms corridor. When he made it to the room that seemed so dull and dead compared to the true Charms room, where students would laugh and experience the joys of magic and the after-effect of the first years joy often left behind a mark on the room making it seem warm and inviting to all, there stood the Potter boy. Snape didn't say anything, he didn't want to take away the joy of seeing a loving family waiting for him from Harry, because no matter how much he hated him at times, he did feel bad for the boy. He'd lost Lily as well, but at least he'd gotten to know her. Once the boy left the room he took slow steps up to the mirror, more than scared as to what he might find. He blinked once, blinked twice, and they were there.
In front of him stood not just his sweet Lily, but himself, both standing behind a boy who looked just like the Potter boy. But the hair was Snape's and that was how he knew. He was his. She was his. This was the Snape's as they would have- should have been. Or it was just a figment of his imagination. The logical part of his brain knew this was just a trick but the mirror did a nice job of clouding up that part and pushing it away,and Snape stared at the people in front of him as though they were there. And in some ways, they were. Just centimeters apart but centimeters he could never cross, a barrier he could never break. Because he had been foolish. Childish. Idiotic.
As the sane part of him got buried back further and further, Snape was overwhelmed. The logical bit of his brain was screaming at him to do something, run away, hex off the mirror, but its screams were clouded and muted out. The what if's took over and somewhere in between thoughts of 'if only' and 'I should've...' he fell to his knees, hands on the glass as though he was trying to grab them, pull them out of the mirror and just make things okay, but he couldn't. Sobs wretched through Snape's body and tears streamed shamelessly down his face, the cold hard pretense just fading away and leaving behind what was left of that foolish teenager who thought anything was possible, who had big dreams for him and his Lily.
What seemed like hours passed in a couple of minutes, and barely 10 minutes before Snape broke down his watery eyes turned towards whoever had put his hand on his shoulder. If he had still been thinking things through at this point maybe he would've expected Albus or one of the other professors, but certainly not who he found. Harry gently wiped off the mans tears, his eyes showing understanding and knowledge and kindness far beyond his years. Snape couldn't help but pull him in tight because even though the image in the mirror was impossible, Harry was here, and not only was he from the mirror but he was the very example of impossible. He'd survived the killing curse after all.
Harry made no move to pull away, let out no gasp, he just let Snape cry. After a long while and after the tears had stopped, Harry looked up at Severus Snape."What do you see?" He asked softly.
"I see the what ifs." Severus replied after a time. Harry was vaguely reminded of a bit he'd found in a library book.
'I see the what ifs at the end of the road, I see them lurking behind every corner. They're the shadows cast down the alleyway from street lamps shining overhead, the tears I cried and those never shed. There they wait to capture me, pull me into a twisted reality. Of what could've and what would've. What if I had done this and what if I had done that. The what ifs are dangerous, they hurt the best of us. And maybe I should've and maybe if I had, but I didn' if you didn't look to the past you wouldn't learn from mistakes but questioning those mistakes, that's where it gets tricky. Because the what ifs want you, they pull you away. They tear you limb from limb, pulling you apart as you think of those words you'd never say. What ifs are uncertain and day after day we deceive ourselves, trick ourselves into thinking we know what would happen if we hadn't done that.
But do you? Do you really?' Harry just rested his head back on Severus' shoulder and hoped he could save him from the grasp of the what if's.