The bell rang, signalling the end of Potions, when Cassi heard something she thought she'd never hear again.
"Miss Renner."
No one else seemed to notice the quiet phrase, but Cassi froze, abandoning the equipment she was packing. I think Snape just said my name. Surely he wouldn't want to talk to her so soon after the whole Malfoy fiasco - unless she was in trouble. She swallowed, then quietly said, "Yes professor." She stayed where she was until the room was empty, then cautiously approached his desk, avoiding looking at him. What would she see if she met his gaze? Hurt? Anger? Disgust? She didn't want to know.
Nerves made her forget the details afterwards, but to the best of her memory, Snape had emotionlessly told her to meet him that night in the classroom for Defense lessons. Cassi had agreed without thinking, just thankful she wasn't being punished, but in retrospect as she lay on her bed before dinner, she wished she hadn't. You know you're just going to end up saying something stupid and making him more upset, she berated herself. Besides, even if he doesn't show it, you know he's mad at you. How could he not be? Think of how...that night must have looked to him. She shivered. If you ever wanted a chance with Severus Snape, you blew it.
Finally it was time to meet Snape. Dinner had come and gone like a blur, moving far too fast for Cassi's taste - although she was happy to get out from under the cold, detached glare coming from the teachers' table through the entire meal. Cassi locked the door of her dorm, hoping her roommates wouldn't be back soon, and began hunting through her Muggle clothes. Unlike the other times Snape had given her lessons, tonight she was supposed to wear something more normal than her robes. Snape had warned her with a sneer that her lesson wouldn't be a piece of pie and that it might be a few hours, so she decided to wear lighter clothes. She never noticed that her top showed off the new scar on her neck and the old ones along her arms.
Before she knew it she was opening the door to the Potions classroom. Snape stood near his desk facing away from the door in the empty room. The only light came from a lamp and a few candles, making it hard to see anything that wasn't directly lit. Cassi quietly closed the door behind her, stood looking at him for a moment, then sat down at one of the backmost desks. For a moment everything was still, then Snape spoke.
"Do you know what Occlumency is."
It was phrased like a question, but spoken like a statement. Cassi answered quietly, "Yes, professor. It's when -"
"And do you know what a Legilimens is."
This time, Cassi just said, "Yes, professor."
After a pause, Snape turned and looked at her. Their eyes met, and Cassi hated how distanced and unfeeling his gaze was. Suddenly she just wanted everything out in the open. She stood from her desk and began to walk toward him. "Professor, please, I'm so sorry, Malfoy just - I didn't have time, I wa-"
"Not now, Miss Renner!" he snapped, eyes flashing. Cassi immediately stopped. All pretense was out the window, and Snape was making very little effort to mask his betrayal. "If you don't mind and can refrain from regaling me with your tales of woe and regret, we will continue with your lessons which, may I remind you, are being administered at your own request!" His glare dared her to contradict him, something she had no intention of doing. She was still recoiling from his outburst. They continued to stare at each other, each seeing the pain in the other's eyes, then after a brief pause Snape turned swiftly and began to pace the room, throwing a myriad of hazy shadows on the walls.
"Years of training and practice have allowed me to become proficient in both Occlumency and Legilimency. Tonight I will teach you Occlumency." He glanced at her scornfully, his expression saying that he seriously doubted she would succeed. He continued, "I will break into your mind. Stop me." And without any more warning, he pointed his wand at her and said in a deadly quiet voice, "Legilimens."