Severus gripped his desk tightly, the hard ridge cutting into his palms. Boisterous laughter filtered in from the corridor outside; not even the heavy wooden doors deadened the sound. They sounded happy. Gleeful. Mocking. Of course they would be, those brats.

Shoving back from the desk, he stormed from the DADA classroom. His footsteps thundered against the stone blocks, causing his robes to whip around his ankles as if blown by a gale.

A handful of sixth year students milled around the corridor.

'Potter's a legend,' Corner declared, his eyes shining with mirth.

'Michael — '

'Five points from each of your houses for noise disturbance,' he snapped, in such a dirty mood that he didn't bother to check if there were any Slytherins among them. Let them lose points; he would not tolerate disrespect.

The students shushed. They looked between him and each other with wide eyes before scattering like gobstones after a strong hit.

'That will be another five points apiece for running inside the castle.'

Their steps slowed, but even then, they walked as quickly as they could without crossing the line to running. No doubt they'd sprint again once they escaped his line of sight.

As long as they were gone, he didn't care.

There's no need to call me "sir", Professor. Potter's voice rang in his mind, louder and more haunting than any school bell.

That smug little worm — that arrogant brat — that insolent miscreant —

How dare Lily die for him? The boy was half Lily, yes, but he was all Potter, with his arrogant belief that he was above the rules and that everyone and everything should make way for him. Worse still, the other professors humoured his delusions, not only excusing his rule-breaking but, in some cases, rewarding it.

Perhaps that was only to be expected. After all, the same staff had eagerly turned a blind eye to his father's failings.

That Halloween, the world lost a shining light to keep a muddy blemish.

The hem of the last student's robe slipped around the corner. Turning on his heel, Severus retreated to his classroom, which was now mercifully quiet. He took a deep breath and pictured — no, he couldn't picture the park he'd played at with Lily. Not today, not when Lily was so entwined with the source of his agitation. Instead, he visualised himself chopping up ingredients into thin slivers, each slice calculated and precise. His racing heartbeat calmed as he slowly exhaled.

Opening his eyes, he magically cleared the blackboard. His next lesson was first years, fresh off the train to Hogwarts. Some of them might try to test him to see how much they could get away with, but they would be easily intimidated into good behaviour. None of them would show such cheek.

But as wrote a list of rules for them to copy down, an uncomfortable thought niggled at the back of his mind. Harry Potter's disrespectfulness came from his father, but the words themselves echoed with the remnants of a breathier voice. His jab was the kind of caustic wit Lily adored; how many times had she muttered something similar to Severus during particularly trying lessons?

Her sass was one of the things he'd liked most about her. Nothing was too precious or too scary to mock; no one, however important, was too superior. Few people realised just how brazen she could be when she let her Cokeworth roots peek through.

Severus suspected that his appreciation for her humour was one of the things that had drawn her to him in return. Unlike her fellow Gryffindors, who subscribed to a black-and-white view of the world, he liked her irreverence. He could even match it, although he knew his jokes had sometimes skewed too dark for her tastes.

Now, her wit had been weaponised against him, the person who used to share and revel in it. Like everything else about Harry Potter, Severus could see his mother's influence, but it was overshadowed by his father's. That was the worst part; everything that had shone so bright about Lily was now irrevocably tainted.

Chatter built up outside the door as the first years began to gather. With a jolt, Severus finished the list of rules and covered the distance to the door in several quick steps.

Potter was beyond hope, but perhaps this new cohort would have more potential — both as potioneers and people.

They certainly couldn't have less.