In a bout of insomnia, Agatha Peale had been pacing about the castle every night for three weeks. She had been pacing up and down this particular corridor for no less than four entire evenings and had yet to encounter anyone, save for the portraits on the wall, and all of them were snoring soundly. Her idle walks about the castle were isolated and lonely—being a new professor, she knew very few people her own age, save for her students, who seemed to like her style of teaching.
She gathered from some of the older students that the man that had held her position before had been a "greasy git bastard"—put into words by an enthusiastic, then blushing fifth year. Agatha had seen the man whose place she had taken leering at her in the Great Hall during all possible meals. At first, she had been nearly frightened of his angry stares, but she had adjusted and wasn't quite as uncomfortable. She found comfort in the fact that her students thought her to be the best Potions professor they'd ever had, and she was especially kind to them when the "new" herbology teacher, Professor Snape, gave them many rolls of parchment on a decidedly minute, insignificant and remote concept relating to wizarding flora. Her students said this was less out of a desire for learning and more out of spite. She believed them to be correct.
Agatha rarely bothered with the Lumos incantation as she paced the halls. She knew her way by now. She walked endlessly, thinking with her dressing gown clenched tightly to her, rarely looking up and breaking her concentration. On this particular evening, she was contemplating teaching her fourth years a potion to temporarily change the color of the drinker's skin—the Colorare-Corpus potion, and her seventh years a similar, but more difficult potion that gave the same results, but with a pattern instead.
She had just begun to make a mental list of the ingredients she needed to gather from the store room when she collided headlong with something decidedly human. She brandished her wand, shouting "Lumos!" and pointing it in the direction of the figure she had collided with.
"Oh, come now, Miss Peale," the figure said in a droll, almost bored voice. To her extreme dismay, his wand was in the same ready position and probably more accurately aimed than her own. And, to make matters worse,, she had collided with none other than Professor Severus Snape.
"No need for all this wand waving, Madam..." he continued. Agatha noticed he made no motion to drop his wand.
"Professor Snape," she stammered. "I didn't know..."
"I know...I've followed you for the past several evenings. Your insomnia is almost as great as mine. Although mine is the result of my...recession to herbology..." he said, drolly but pointedly, smirking menacingly.
That was it. He was going to attempt to oust her out of her position by intimidation. His stupid smirk said all she needed to hear. The unease she felt was justified, and she was angry.
"Now you listen, Mister—Professor Snake—"
"Snape," he snapped in correction.
"Snape. You can't intimidate me—"
"Keep your voice down, Miss Peale. Need I remind you that it is forbidden for students to roam the hall at night and inadvisable at best for...professors to do the same?"
He was trying to goad her and she knew it. His smirk cracked into a rancid, half-smile.
"Then, why, Professor Snape, are b you /b roaming the halls?"
The smirk faded.
"Now you look here, Miss Peale. I strongly advise against making enemies so early in the term and in your career. You never know—"
"You can't frighten me!" she shouted back, re-raising her wand to his chest.
"Then don't act frightened," he sneered back, attempting to pluck the wand out of her dangerously steady hand between his forefinger and thumb.
"You don't seem intent on conversation but rather a lengthy duel, Miss Peale," he said, nonchalantly.
"Are you challenging me?" she asked reluctantly.
"Why ask me? You're the one with the wand pointed at my throat," he replied coolly. The smirk had returned.
"Then, challenge."