Harry Potter. He's here. Lily and James' son. He's here.
He has her eyes.
Severus Snape was pacing the floor of his office long after all the students should have been asleep, trying to figure out why in the name of Merlin's beard he didn't hate Harry Potter's guts.
Harry was the exact image of James Potter, the man who had annihilated any aspirations Snape had ever had of living a happy life. Potter had stolen Lily Evans, the girl who had stolen Snape's heart back when they were in school. Well, ok, Snape had liked Lily even before Hogwarts. But it was at school that Potter had entered the picture. Potter, with his arrogance and good looks and popularity, had stolen Lily from him. How? he asked himself. How could Lily have chosen Potter over me? What did she see in him? Surely there was something there. Something besides being a good athete and being popular. I treated her poorly, once, but Potter and his whole gang were prats to everyone as a pastime. I may not have been the best, but I certainly didn't deserve to be beaten out by Potter.
He fumed as he sat at his desk, chair swiveling to a stop as he stared at the wall. I have never deserved this treatment. I never deserved Lily, either, he thought as his gaze softened, she always deserved so much more than anyone here could have offered. He knew in the core of his soul that there was nothing he could have done to win Lily, regardless of his behavior and regardless of how well and how truly he loved her. Even his best put him nowhere near her level, and there was nothing he could do about it. It was easier, however, to think that life was unfair and that Potter was a git that never deserved Lily, either. Even so, the truth he knew meant that he couldn't hate Harry, not when the boy was half Lily and half Lily's choice.
Why couldn't she have picked someone else - anyone else? Snape turned back to his desk and began sorting assignments that had been turned in that day. It was late, he wouldn't grade tonight, but the action of sorting the parchments was therapeutic. Even Lupin with his issues would have at least been understandable. Lily always did like an underdog, he recalled fondly. Every Quidditch match, every owl that got sick, every student struggling with Charms...she was there for all of them. She was there for me.
He continued sorting in silence for a bit. When the stack was gone, he leaned back and stared at it pensively. Lily had always been highly intelligent and was willing to help many students with their homework, but that had never been her favorite part. She loved the practicality of her education and was always Charming or Transfiguring the simplest, most beautiful objects. She had spent many hours with Snape walking outside in the summer or sitting in an empty classroom in the winter, not speaking a word but simply taking turns sharing magic. Creating showers of sparks that change color, making storms out of the dust in the cracks of the walls, helping a rosebud bloom in a matter of seconds, twisting branches into ornate knots, animating pebbles and making them dance. Lily had always been the one to draw out the inner beauty of an object when her magic touched it; Snape was the one to make it bolder and stronger. And somehow, those two things went together perfectly. The beauty of Lily's flowers tempered the darkness of Snape's sandstorms, but when Lily died, there was no one to create that balance anymore. It was just him, living life the only way he knew how, needing another half of himself to rest in balance again. After Lily, he had not found another who could fill the void. He hadn't tried very hard to find someone; he hadn't truly wanted to.
For the first time in ten years, Severus Snape allowed a single tear to escape his dark, tightly-shut eyes. He whispered to the empty room, "I miss you so much..."