December 1991
He had been patrolling the hallways that night. Each corridor was brightly decorated with wreaths and candles, souring Severus's already dour mood. It had been an exceedingly rough term so far, having to deal with both Quirrell and Potter. While he knew having the Potter spawn as an almost daily reminder of both the worst years of his life and the life he could have been living, was going to be difficult, it was getting to him more than he had ever expected.
The Potion's professor was just about to finish his nightly patrol when he saw Harry slip out from seemingly nowhere.
"And what brings the Gryffindor prince out of his tower at this time of night?" Severus asked the young Harry, making it clear that regardless of his answer he would at least be getting detention for wandering the hallways at night; just like his father had.
"Why do you think it's any of your business..." Harry defiantly replied, leaving the lack of "sir" or "professor" hanging disrespectfully between them.
The real Severus could feel the anger rise within his memory-self as he waited to see how this moment would play out. Which reality was he watching? How would this Severus react?
"Don't you dare talk back to me like that, you insolent child," memory-Severus bellowed.
Standing as a spectator, Severus saw it. The look in his memory-self's eyes and he knew what was going to happen; he wasn't going to walk away as he had in this reality. Again, he felt his anger rise, but this time not against the child, but himself. Something good would eventually come out of this moment; like a Phoenix, they would rise from the ashes.
It was like watching a horrific accident, he didn't want to see it but he could not turn away. The 31-year old memory-Severus lifted his arm, losing control of his anger, not for the first time in his life, but definitely the worst. His hand came down towards the small 11-year old, with every intention of hitting him. He came so close; too close before pulling away at the very last second.
For all the times he'd played this moment back to himself throughout the years, he always saw that horrible look of acceptance within Harry's eyes when he thought he knew what was coming. As if he was not at all surprised that an adult with authority over him would respond to him in violence. This time, viewing the memory from a different point of view, he could see his younger-self's eyes, when he realized he saw himself in the young boy and knew exactly what that implied. Not only had this boy been hit before, but he was so used to it, he had come to accept it.