So, he waited, and he watched. He followed her through the grounds. He advanced the towers and monitored her movements. She would be alone soon, and he would show her what a Dark wizard on the side of 'good' really was. She had underestimated him, and she had no power here.
The moment came a week following.
He wondered if she had noticed his presence earlier; she made the odd uneasy shift of her eyes. He tracked her through the corridors down from the library, the heels of her shoes clipping down the staircases towards the transfigurations classrooms. It was becoming dark as the evening crept into night. The mullioned windows revealed a moody sky beyond; clouds masking the moonlight, a shadowed, starless canopy.
Hermione stumbled attempting to increase her speed. Her breathing quickened; she was sure someone was there. She gave a nervous glance behind her, and Snape was able to see she was clutching a small collection of dusty books to her chest like a shield. Her wand was nowhere in sight. Perfect.
He paused behind a blackened suit of armour, cloaked from view. He filled his lungs with air that felt heavy. He needed to be closer. But her footsteps were no longer sounding down the echoing hall. She was tentatively tracing her steps back with curiosity and courage. Good. Let her come to him.
He stepped out before her without a flourish, looming as a tall, dangerous shadow. With a single, practiced movement he pressed his hand, cupping it over her chin and mouth, and pushed her full force behind a statue. He felt the back of her head hit against the stone wall. Holding her at arm's length, the fingers and thumb of his hand pressed uncomfortably easily into her soft cheeks. With his other hand he brought the tip of his wand into her neck and advanced it slowly, pressing it hard into her skin until he felt her face struggle against his hand. He dared her to make a sound.
They stood silently and still for a moment. The fear in her eyes was unbaiting even as she recognised her assailant. She made no move to escape. He ignored the passive feeling of her lips against his palm as he pressed it into her more firmly, securing his grip. He wondered if this alone would alarm her sufficiently to keep her away from him, or would he have to do more? He'd gotten away with even less of a threat in the past.
He deliberated entering her mind with legilimency. Perhaps he could look and be certain he had done enough. She dropped her arms to her sides, and her books thumped to the floor. The sound caused him to release her and she gulped in air.
"Do it." She gasped.
He considered her. Her face bore a red mark where his hand had been. She was breathing raggedly - maybe he had pushed too hard. He clenched his wand more tightly. How was she still making him feel like she was in control of this?
"Do… what?"
He watched and allowed her trembling hand to reach out towards the tip of his wand before bringing it to her temple firmly. Her eyes didn't leave his confused visage.
"Remove yourself from my mind, from my feelings. Obliviate me. It's too hard like this."
"I should." He reacted, taking a decisive step forwards and pushing his wand harder into the side of her head, causing her to reluctantly lean her defiant head away from him. She closed her eyes and inhaled a slow breath through her nose as if it were her last. He could almost smell her fear and yet she refused to move from him. He dropped his wand arm. This wasn't working, she thought he was a good man still. But good men did the right things; the things that he couldn't do. He had a long way to go.
He looked down at her, and for a fleeting moment he felt an urge rise within him to press her against the stone and kiss her hard, hard enough to feel her gasp into his mouth.
"Go back to Gryffindor tower." He fired her the fiercest glare that his dark eyes could expel, his teeth almost bared. His cheeks seared hot. "Now, Miss Granger," he growled and didn't wait for her to move before marching away. His robes whipped wildly behind him. He cast a fire-red spell recklessly into the darkness and all the portraits in the corridor fell from the walls.