Just a (very) little oneshot based off a prompt I saw on Pinterest. Enjoy!
Professor McGonagall sighed and pinched the bridge of her nose. It was 8am and she was about to start the first day of the new year, a day she knew from experience was filled with terrified first years and cocky fifth years about to start their OWLs, with no idea how difficult it was going to be. Unluckily, Mondays were also the days McGonagall had no free periods. Ah the joys of being a teacher she thought to herself grumpily. Deciding she had better get to the classroom to prepare, she started to make her way down the castle's chilly corridors.
Like most mornings the paintings were just waking up and starting to sleepily murmur good mornings to their neighbours. Unlike most mornings, there was a large clump of first and second years loitering in the corridor. McGonagall frowned and started over to the group, preparing her bad first impressions speech in her head. However, as she got closer, she stopped and the frown smoothed away when she noticed that the children were gathered around none other than Sirius Black, who was giving advice to the students!
*Flashback*
"I could've sworn Professor Sprout said it was down this corridor!" A little first year glanced worriedly around as she argued with her friend, who sighed, looking frustrated.
"Well you must have heard wrong, because it's clearly not down here-oof!" The second first year broke off mid-sentence as she crashed into a tall, broad seventh year and fell backwards onto the floor. "Sorry!" He squeaked, having heard horror stories from his older sisters about what could happen to first years if they angered the older students. The seventh year, who already looked like he was having a bad day, laughed?
"Careful there, kiddo!" He squatted down and stuck out a hand for the first year to take. After they were both back on their feet, the seventh year shook his head, remarking, "Merlin, you two look terrified! Am I really so scary looking?" Neither replied. "I'm going to pretend you said 'no'. What are your names?"
The first years glanced at each other, before the one who fell over spoke. "I'm Mark, and this is my friend Jenny." Jenny waved awkwardly.
"Well, Mark and Jenny, I'm Sirius. Let me guess, first years?" Nods. "Lost?" They nodded again. Sirius nodded gravely, turned, and conjured a chair in the middle of the corridor. "Well then, you're going to want some help then, aren't you?"
Sirius sat himself down and beckoned the children closer. "And you three over there, who are pretending they're not listening. Come on, you're obviously lost as well." They shuffled over, looking embarrassed. "Okay, so. The trick to working out this castle is really simple…"
*Back to present*
McGonagall considered jumping in, as class was about to start soon, but didn't want to interrupt Sirius as he explained to the students how to avoid getting tricked by the moving staircases. She smiled slightly as she took in the changes to the not-so-young-anymore troublemaker. She had always know that he had a heart of gold, despite his family background. She turned around and took another route to the classroom, resolving to look the other way next time he messed around in her class.