Disclaimer; Please, ask for tamper-proof government ID from all job applicants. Perhaps a background check may be useful…
"Thank you for coming on such short notice, may I offer you a lemon drop?" Dumbledore asks as a cloaked figure enters his office.
"No, thank you. Shall we continue with the interview?" He asks.
"Certainly. How many years experience do you have studying the Dark Arts and Defense against them?"
"I have studied most of my life, just over fifty years now. I am quite proficient in all of the standard defense techniques and have discovered a few new ones along the way. I have many years experience training others and assigning tasks."
"Excellent! What are your views on classroom discipline?"
"I am a firm believer in rules and order. If I give instructions I expect them to be followed immediately and without question. I do not have trouble assigning appropriate punishments where necessary and I don't show favoritism along house lines."
"You sound like a no nonsense kind of person. That's good; we haven't had someone like that teaching Defense since Professor Merrythought back in the forties."
"Yes, I remember him fondly. Taught me a lot in the beginning."
"He was a remarkable man. Now I am afraid we have to ask some more troublesome questions. Tell me sir, have you killed anyone within the last six months?"
"Good, that's reassuring. Have your actions lead to the death of others?"
"Yes, I may have been responsible for one or two..."
"Hmm... Not so good. Well anyway I'm sure you didn't mean to. Are you planning on killing anyone within the next year?"
"Unfortunately I think it will be unavoidable."
"Hmm, yes we are at war after all. Can we at least ask you not to kill any students?"
"I'll try to restrain myself, but if the rumors of that Potter boy are true… I hear he killed one of his teachers and two more are now in St. Mungo's psychiatric ward? Even if I survive, that's half of his Defense instructors he will have killed or permanently incapacitated. Given that I am being hired to teach defense, it might be necessary to practice that in self defense."
"Mr. Potter is a special case. If you have to kill him, wait until May when he gets his yearly dose of chaos. But the rest of the students, can we agree not to kill them?"
"Ok, if you insist. But I would remind you that pain can be a wonderful training aid. Like electro shock therapy it helps the brain associate wrong actions with consequences."
"An interesting observation, but not one we encourage at this school. Finally, and this one is important, do you serve the Dark Lord?"
"I suppose that will have to do. Better than half of the other Professors in recent years. Two were death eaters, one a Dark Creature, and the last while not actually a supporter certainly aided His cause. So long as you can show me an unmarked arm, I think this interview is over."
"Not a problem at all," he said as his long boney fingers pushed up the sleeves of his robe to reveal two very pale forearms. Both were unblemished and unmarked.
"Welcome to Hogwarts Mr. …"
"Everett Marvolo Nigma, but feel free to just call me E. Nigma. I prefer it that way."
"Excellent, like I was saying, welcome to Hogwarts Professor E. Nigma. By the way, I caught a glimpse of your wand, very unusual."
"Yes, it is rather unique, thirteen inches of yew. I don't know of another like it."
"Quite remarkable. The Dark Lord actually uses a yew wand."
"You don't say… Yew wood is commonly found in cemeteries and is quite springy. It makes for excellent wands for the Dark Arts or their Defense. Just enough swish and bounce to get the subtle swirls and flicks."
"Well I won't hold you any longer; your quarters are behind the statue of Ulrich the Unshakable, down on the fourth floor."
"Thank you Headmaster, have a good evening."
"Shush! I want to hear who the new defense teacher is!" Harry hissed to Ron and Hermione who were having yet another lover's spat. Honestly he was beginning to feel he should just lock them in a broom cupboard until they shag and can be civil to each other.
"Sorry mate." Ron replied through a mouthful of pudding.
"… And finally I want you all to extend a warm welcome to our newest DADA instructor, Professor E. Nigma. Professor, why don't you give us a short introduction?"
Harry suddenly got a very bad feeling about this…
"Certainly Professor," a familiar voice replied sounding too happy. "Mr. Potter would you come up here for a moment please? I want to give a practical demonstration very quickly."
The sense of dread increased. Harry didn't know who the man in the cloak was, but he was certain he knew him as someone other than Mr. Nigma. He slowly rose and approached the head table as the students whispered and gossiped speculation.
"Thank you Mr. Potter, may I see your wand for a moment before we begin?"
The only reason Harry even thought about agreeing was that September was far too early to be May, so this couldn't be his yearly death threat. He handed over his wand.
"Avada Kedavra!" And Lord Voldemort, alias Tom Marvolo Riddle, alias Everett Marvolo Nigma, threw back his hood and celebrated his victory. After nearly fifteen years of constant work, the brat was dead! All because Dumbledore was far too trusting to check ID.