Now I have been doing a fair bit of research to make sure I'm getting details correct, although some aspects may be completely made up and not of the typical wizarding world, or may not completely correlate to the layout and curriculum of Hogwarts. I am trying though :)

Snape stood upright, next to the blackboard, with his hands behind his back. He had Gryffindor and Slytherin 7th years as his very first lesson. He wasn't particularly looking forward to it, he despised being in the same room as the Weasley twins. Snape glowered at the door as he heard the first group enter the room. A bunch of Slytherins. It made sense that they were the first to enter, as their common room was on the same floor, but it also gave him reason to scold the Gryffindors. Oh, how he wished the last person to enter to room was a Gryffindor, perhaps that'd be his first load of points to deduct from the pathetic house. A few more students entered the room, this time Gryffindors. He glanced around the room, taking note of all the students in the class. He knew he would have a small classroom this year. He had only expected 9 students.

After a minute longer of waiting, Snape heard a racket in the hallways. He sighed. The Weasleys. They entered the room with unnecessarily cheesy grins on their faces. Snape eyed them dangerously, as he watched them take their seats. They barely flinched under his threatening stare, but there was something, some small sign of fear. That pleased Snape more than anything.

He pointed his wand to a pile of books which dispersed onto each students' desk. He hated using the books that the students purchased from Flourish and Blotts, he always thought his own findings more accurate.

"Today we'll be brewing a simple sle-" Snapes eyes flung violently to the door, who on earth would dare be this late? He saw the small blond girl walk in and sit on her desk. "Miss Byron," he drawled, "How very brave of you, waltzing in 5 minutes later than asked of you." Snape glowered at her, as dangerously as he could. He was surprised to see she didn't flinch in the slightest. "See me after class, so we can deal with your pathetic time keeping." Snape again looked displeased when he saw no reaction from the girl. Nobody, not anyone, could withstand his brutal stare. Silly girl probably didn't know how dangerous he could be. "As I was saying, we will be brewing a simple sleeping draught, the instructions are on page 47. If any of you shall fail to brew this simple potion, then you'll be in detention scrubbing cauldrons. Am I clear?" Snape looked dangerously from student to student, to ensure his threat was taken seriously.

Hannah was familiar with how to brew sleeping draught, although her technique was somewhat different to that in the book. She read over the instructions. Wave your wand? These people think you need to wave your wand in order to brew a potion? Are they honestly that ignorant? Angered by the ignorance of some people, Hannah decided to just follow the instructions in the book, considering the only ingredients placed in front of her was that of the ones written in the book. She added the Lavender, Valerian Sprigs, and Flobberworm Mucus to the cauldron the way the book suggested, but instead of waving her wand, she waved her hand over the cauldron.

Snape walked around the room slowly, staring uncomfortably over the students shoulders as they worked. Everyone seemed to have their potion perfect, except for, of course, the Weasley twins, who purposely made a mess of the potion to anger their professor. "I assume you two think yourselves funny for proving you're both a complete disgrace?" Snape drawled. The twins looked up at Snape simultaneously,
"Actually," George started,
"We think ourselves having a lot more fun than the rest of your students." Fred finished.
"If it hasn't occurred to you," Snape scowled, "school is meant to be about achievement, not fun."
Snape deepened his violent stare at the twins, "and the potion was in fact meant for the hospital wing. Do you find amusement in depriving the ill of their medication?" The twins looked at each other, frustrated that the professor actually made a good point.
"I'll be seeing both of you after class. You can accompany Miss Byron with scrubbing cauldrons." He glanced in the direction of Hannah, to see if she reacted in any way, and instead found himself staring at a girl who had her head face down, on her arms which were rested upon the desk. How dare she look so bored in his classroom? An unfamiliar voice inside his head spoke, "Maybe it's because you only set one simple piece of work, or hadn't that occurred to you?" Snape focused his eyes back onto Hannah, then realised she was staring back at him now. Snape decided to let it slip by, and continued to scold the twins instead.

Everyone else had left the classroom, so only Snape, Hannah, and the Weasley twins were left. "Weasleys, return after dinner, you'll be scrubbing every single cauldron in this room with your bare hands, without magic, alongside Byron." Snape glanced at Hannah, once again to see no expression on her face. "Weasleys, go to your next class. Byron, stay behind." Fred and George left the room without turning back, whacking each other in the arm accusingly.

"I suppose, Miss Byron, you have a reason to have been late. Perhaps you got lost? Failing to follow my simple instruction to stick with Draco. I suppose a silly little girl like yourself thought yourself too clever and important to be shown around." He scowled at Hannah, surely this'll set her off. Serves her right for walking into his class late.
"I was with Dumbledore."
Snape glared at her. So she does have a reason. How can I pick something out this time? I can't let a silly little girl out argue me.
"That's professor Dumbledore to you. I suppose you think yourself too important to acknowledge people by their proper names?" That's sure to set her off. He looked at her expectantly, yet still portraying his dangerous glare. Snape heard the voice emit into his thoughts again, "That's rich coming from you, I believe my name doesn't just consist of the name 'Byron'." Snapes eyes refocused, Hannah was staring back up at him. Snape thought the words, "you can hear my thoughts can't you?"
The voice replied, "Yes."

Elaboration on why Hannah has the ability to communicate with Snape's thoughts will be coming up in the next chapters. I promise there will be no gaps in reasoning. Everything written has a purpose :)

Thanks for reading this far, it means a lot :)

Please let me know how my writing technique is, and how I can make it better. Thank you :)