It had been years since the war had ended, and Harry still had nightmares. He still woke up in the middle of the night, terrified that Voldemort would come back and hurt his family. Being an auror didn't exactly help – he was always faced with danger, couldn't escape the PTSD of his childhood. Harry had been an auror for around seven years at this point – and each year his nightmares would get worse and worse. Ginny never said anything, but he knew she worried. Harry wanted nothing more than to make his family feel safe and happy but didn't know how to make that happen. That was, until, he received a letter from Neville Longbottom.
Harry,
I hope you're doing well, it would be good to see you again soon. You probably know that I've been working at Hogwarts for the past few years as professor of herbology, a job which I've really come to love. I know you have your job as an auror (and a pretty good one, from what I hear), but there is an opening here at Hogwarts for the defence against the dark arts post, and I know you'd be perfect for it! You've always been great at teaching – I think I learnt more from you during our DA meetings than I learned from any other of our DADA professors. Don't worry – the curse of the job has gone. Professor Lancaster only left because she got a job offer at Durmstrang. Write back and let me know if you're interested, I'll put a good word in with McGonagall for you.
Hope to hear from you,
Neville Longbottom
Harry couldn't believe his luck. This was it. This was his opportunity to stop the nightmares, to make his family feel safe again. Hogwarts had always been his home, a place where he'd always felt safe. He wrote back to Neville immediately, saying that he'd love the job.
By the time September 1st came around, Harry was feeling ecstatic. It had been years since he had been to Hogwarts and seen Professor McGonagall. It was a few years until his children were due to start school there, so he had enough time to practice his teachings before they came along. This is what he'd wanted for years – a sense of normal. He was no longer The Boy Who Lived or The Chosen One. Instead he was simply Professor Potter, teacher of defence against the dark arts at on of the finest wizarding school in the world. Of course the students wold recognise him, and he knew this, but teaching felt a lot more normal than constantly fighting a battle. He'd done enough of that for a lifetime.
His first class of the term was a group of third years, with a mix of Gryffindor and Slytherin. Harry thought back to his first DADA class of his third year, how engaging Professor Lupin had been. He decided to follow in the footsteps of his mentor and taught his class in the same way that he did – all practical and no theory. Harry smiled and raised his wand.
"Now, kids, repeat after me. Riddikulus!"