It's been 5 years since Sirius started as a flying instructor at Hog warts. Life didn't move too fast, though it certainly did when Sirius watched other people around him. James and Lily were still learning how to properly raise their 4 year old son, Remus still struggling finding a good paying job as a werewolf.
Peter died in a weird Dark Arts accident 4 years ago - the toll of losing their closest friend and one of the marauders to the cause they were trying to fight as part of the Order, but they helped each other push through it.
Students at Hog warts adored Sirius. He was strongly built after half a decade of catching kids mid air and breaking up fights during quidditch games; cool and relaxed flying instructor; beyond average looks, that dare Sirius say, aged well along with him? The tiny whispers and hushed conversation of some of his younger admirers told him so.
Sirius found comfort in teaching at Hog warts - he had company, if not kids during lessons and after school practice, then his fellow staff that were once his own teachers.
Except for the illusive Care of Magical Creatures professor. The new professor.
You rarely retreated from inside your Vivarium, though Sirius always got a glimpse of you when you were in the pens next to the veranda classroom feeding Puffskeins or checking Mooncalfs' temperature - at times Sirius swore he saw you on the back of a Hippogriff flying around.
You peaked Sirius' interest, never too close to actually giving him a good chance at conversation.
The students would whisper contradicting statements and opinions about you in the halls - some thoughts you were too harsh, others thought you were too linient of homework.
The December air blew through the field, making Sirius grip the broom tighter as he supervised the Raven claw Quidditch team practice. It was still 7 in the morning, a few minutes left until the rest of the student body woke up and began their day with a fulfilling breakfast in the Great Hall.
One of the Bludgers was hit hard, sending the enchanted ball out of the quidditch field.
"You all finish up, I'll go get it." Sirius waved the students as he landed on the ground, following the path that the Bludger flew off on. Just his luck, when the Mooncalf pen came up in his view, the magical creatures playing around with the new toy.
Sirius sighed, running a hand through his hair. He's not heartless to just rip the ball out of the creatures' paws, when they looked to cute running around on their short, webbed feet around the ball.
Raising his hand, Sirius knocked on the Vivarium door, hoping the Professor is in there.