Just a Defense Against the Dark Arts Professor: No More, No Less

Professor McGonagall's words threw Sherlock into a state of disbelief. He never anticipated that the position of Defense Against the Dark Arts professor would actually fall into his lap.

Let's be honest, with the original owner's problematic personality, it was a ludicrous proposition. He was a walking disaster waiting to happen, hardly the ideal candidate to teach a group of impressionable young wizards.
The shock evident on Sherlock's face didn't seem to raise any suspicion in Professor McGonagall. In fact, she seemed to expect his reaction. After all, he had been applying for this position for years, and Dumbledore had consistently turned him down.
"I know this might come as a surprise, Sherlock," Professor McGonagall said, her tone understanding. "Three months ago, you approached Dumbledore regarding the vacant Defense Against the Dark Arts position. At that time, he had already selected another candidate."
Sherlock stared at her, his mind racing. "So, there was another professor chosen for the position?"
Professor McGonagall nodded. "Yes, but unfortunately, the appointed professor, Gilderoy Lockhart, has encountered some… difficulties."
Sherlock felt a shiver down his spine. He remembered reading about Lockhart in the diary, the self-proclaimed "greatest wizard of our age." "What happened to him?" he inquired cautiously.
"It turns out that Lockhart had been fabricating his heroic deeds," Professor McGonagall explained, her voice laced with disapproval. "He had been using the Memory Charm to steal the memories of other wizards, claiming their exploits as his own. He was a fraud, a charlatan who built a career on stolen glory."
"He was recently exposed and apprehended by Aurors. The Ministry of Magic will be holding a trial soon, and it's highly likely he'll be facing a lengthy prison sentence in Azkaban."
"With the semester about to begin and the position vacant, Dumbledore believed you were the most suitable candidate, despite your… eccentricities."
Sherlock felt a wave of dizziness. He hadn't considered this possibility. The original owner, with his unwavering loyalty to Dumbledore, would have eagerly accepted this unexpected opportunity.
But Sherlock was a man of the 21st century. He knew nothing about teaching, let alone the intricacies of advanced magic. He was essentially a fraud himself, masquerading as the original owner.
"I… I understand," Sherlock stammered, trying to maintain his composure. "Though I must admit, I'm surprised."
Professor McGonagall, seemingly oblivious to his internal turmoil, handed him a rolled-up parchment. "Congratulations, Sherlock. This is your letter of appointment. You'll be joining the Hogwarts faculty as Defense Against the Dark Arts professor this semester."
Sherlock stared at the parchment, his mind reeling. He had stumbled into a situation far beyond his control. The weight of his new responsibilities suddenly crashed down upon him.
He had to teach. He had to protect students from the forces of darkness. He had to be Sherlock Holmes, the eccentric, brilliant, and slightly terrifying Defense Against the Dark Arts professor. And he had absolutely no idea what he was doing.
Please finalize your textbook selections for the Defense Against the Dark Arts class as soon as possible and submit the list to me via Owl before August. If you plan to travel by the Hogwarts Express, this ticket will grant you access on the first day of term."
Professor McGonagall rose to her feet, her wand appearing in her hand with a flick of her wrist.
Before departing, she smiled at Sherlock. "May Sally bless you, Sherlock. Farewell."
With that, she vanished from the room.
Sherlock remained seated, silently staring at the letter of appointment, the words "Professor of Defense Against the Dark Arts" starkly contrasting with the serenity of his living room.
After a long moment, three words escaped his lips, "Defense Against the Dark Arts?"
Hogwarts, usually bustling with activity during the school year, now lay eerily quiet. The departure of students had left the ancient castle shrouded in an unusual stillness.
Professor McGonagall, having returned to the school, made her way directly to Dumbledore's office.
Dumbledore, clad in dark blue pajamas and a grey beard, was hunched over his desk, immersed in official documents. He looked up as Professor McGonagall entered, removing his crescent-shaped glasses with a weary sigh.
"Sherlock has received the letter of appointment?" he inquired.
"I delivered it personally," Professor McGonagall replied, a hint of hesitation in her voice.
Dumbledore, sensing her apprehension, smiled. "Don't worry, Minerva. If you have any concerns, feel free to share them with me."
"I do have some reservations, Albus," Professor McGonagall confessed, frowning slightly. "I'm delighted that Sherlock will finally achieve his lifelong dream of teaching at Hogwarts. However, his… personality, to put it mildly, can be challenging. I fear he might not be the most responsible teacher for a group of impressionable young wizards."
Dumbledore remained calm, his eyes twinkling. "He yearns for acceptance, Minerva. He longs to prove himself, to show the world that he is more than just a lonely, unaccompanied child. This position, this responsibility, will force him to grow, to mature."
He rose from his chair, walking towards the wall adorned with portraits of former headmasters. "He possesses a remarkable talent, just like his mother. His character flaws, while significant, should not hinder his future. We all need to learn and grow. This experience at Hogwarts, I believe, will be a valuable lesson for him."