A/N: This story was written for Slytherin house in the Houses Competition round 8 as a drabble using the prompt autumn/fall. Enjoy!
Word count (not including A/N): 704
Severus Snape used to like autumn– he would get to go back to Hogwarts, away from his abusive father and neglecting mother, and even though he was bullied at school, it was better than "home", because he would get to see Lily. Besides, autumn was pretty (though he would never admit it). The leaves were red and orange and gold, kind of like Lily's hair in the sunlight, and the air was just the right temperature. Autumn was crisp mornings and long walks alone.
Until eleven years ago. He had stupidly joined the Death Eaters in sixth year, and by 1981, he had the Dark Lord's full trust. The fact that Lily had actually had a child with James Potter still stung, and he had just wanted to do something. Trelawney's prophecy seemed like a perfect way to vent his frustration, and what better way to do that than with this vital information?
He had realized his mistake. Snape cringed behind his sneering facade as he remembered himself running away and crying to Dumbledore, begging for him to protect and spare Lily. He allowed himself to be used, switching sides for Lily, but in the end, Dumbledore did nothing. She had died.
But nobody cared. All that mattered was that Voldemort was gone, and that the son, the Boy-Who-Lived, had, well... lived. Snape was inexplicably angry at the toddler. It wasn't fair that he got to survive and Lily didn't! Snape had given up everything to ensure Lily's safety, and the boy had the audacity to come out of the attack unscathed!
But the only thing Snape could do now was to ensure that the tiny piece of Lily left on the earth, her sacrifice, however connected to James Potter, was kept safe.
Now, as a teacher, autumn (and winter and spring) meant children. Snape despised children, teaching them even more so. But he had to remain close to Dumbledore, even if the man had talked him into this position in the first place. Summer, once his least favorite season, became his sanctuary, when he didn't have to deal with homework and grading and detentions and exploding cauldrons. Fall, once his refuge from the Muggle world, became a source of dread and apprehension, when he would be introduced to yet another group of pests that he would have to teach for yet another seven years. After his fifth year of teaching, the students all just blended together. It's all for Lily, all for her son, was his mantra throughout the long years of waiting until the Potter child actually came to Hogwarts.
But when Potter did come, it was like a smack in the face. Here was the living proof of Lily's marriage, and Snape was so filled with loathing he could not think. He was determined not to let this boy, who looked painfully like his childhood tormentor, get under his defenses, no matter what he had promised Dumbledore or why he became a teacher. As the weeks went on, Snape was unforgiving and biased, but he didn't care– this was his way of venting everything James Potter had ever done to him. A flicker of guilt lived in the back of his brain, but he pushed it aside.
The only bright spot on the Halloween day was that he didn't have first year Gryffindors. He only had one class (fourth year Hufflepuffs and Ravenclaws) and then he would be free to mourn in peace until the feast.
Sitting in his office, drinking mead and reminiscing about the few good childhood memories he had, the guilt in Severus' mind grew and grew. She's gone, he repeated to himself. She's gone because of you, because of that stupid prophecy. What are you doing teaching here? A lone tear made its way down his prominent nose.
The clock on the wall chimed. He stood up, hastily putting away his mead and wiping his face to make sure there was no evidence of his crying, and made his way to the feast.
.oOo.
Staring at the wreckage of the girls' bathroom, at the water covering the floor, at the mountain troll on the floor, Snape realized why he became a teacher. I have to protect this boy.