The next evening Hermione arrives in front Snape's office right after dinner. Despite his earlier admonitions, she still gives her self a minute to compose herself. When she does knock, the door swings silently open. His desk is empty, save for a stack of third year essays, a bottle of red ink, and a quill.
An hour later when she reaches the end of the stack of papers she finds a note:
"Come into the lab and evaluate the first year's shrinking solutions. Do NOT disturb me."
Hermione gets up from the desk and makes her way through the door and into Snape's private lab. She can't help but gape a little as she steps through the door. Carved wooden tables hold his equipment – most of which Hermione doesn't even recognize- and the walls are wall to ceiling book shelves crammed full of books. The air is fresh, obviously there is some sort of magical ventilation system. Snape has his back to her- he is standing over a small cauldron the color of mercury, muttering an incantation. It takes all of Hermione's self control not to just stand there and watch him work.
She turns resolutely to the neat row of first year potions and begins the painstaking process of evaluating them with spell work. She ignores the bucket of toads set out next to them, shuddering. She still remembers the look on Neville's face when Snape tested a potion on the boy's familiar, Trevor.
At ten o'clock, she still has four potions left, so she decides to stay and finish. She is in the process of decanting the first potion when Snape's voice startles her, "It's past ten, Miss Granger." She almost drops the potion. She steadies herself and finishes decanting it.
"Only four more, Professor."
"You could have finished in half the time if you had used the toads I provided," Snape says, casting a stasis spell over the peculiar silver cauldron. He glides across the room toward Hermione. The combination of that low, sonorous voice and the bat-like gliding is, to Hermione, compelling and creepy at the same time. She has to concentrate on not visibly shaking as he approaches her. "The Headmistress made it clear to me I was to release you by ten."
"Yes, Professor," Hermione says, backing away reluctantly from the last of the shrinking solutions. She glances furtively at the bucket of toads.
"For Merlin's sake, Miss Granger, I do NOT need live toads to test a first year potion!" he snarls. He snatches the quill up off the table and proceeds to grade the last four potions, without doing more than glancing at them.
"But you- Trevor- Neville-" Hermione stutters, managing to look horrified and confused at the same time.
Snape looks down at Hermione for a moment, as if considering what to say. Then, "Miss Granger, I would think that you, of all people, would be clever enough to realize the point of that exercise. Think on it, and come back to me tomorrow with your answer. If it is satisfactory, we will continue your detentions. If not…" He turns away abruptly and glides back to his potion.
The next evening Snape's office is empty again. Hermione sits down and slogs through two stacks of poorly written fourth year papers. By the end of it she has the beginning of a colossal headache, and it no longer takes any effort to be cutting and sarcastic in her remarks. She almost feels sorry for Snape. Almost.
As she finishes the last paper with two paragraphs of biting commentary and a failing mark, Snape swoops into the office behind her. The air from the door swinging shut behind him sends the papers whirling off the desk like leaves in an autumn storm. Hermione quickly summons them back with a nonverbal spell and then looks up at Snape. She is still holding the final paper. He holds out his hand. She puts the paper in it.
Hermione watches Snape's face as he reads the paper, his expression turning from bored to sour. For once, she thinks this expression is entirely appropriate. When he reaches her remarks, and subsequent grade, his eyebrows go up slightly and the deeply ingrained sneer vanishes from his face entirely. Is this surprise? Approval? Hermione can't tell. He looks up from the paper.
"Careful, Miss Granger," Snape says, his voice low and expressive, "If you continue to grade like this I'll keep you in detention all year."
Hermione allows herself a small smile, and stays silent, looking up at him without breaking eye contact. His face, she realizes, isn't altogether unpleasant when he stops sneering.
"Now, about yesterday's discussion," he says, "Do you have an answer for me?"
Hermione purses her lips at this. She wants to say, 'yeah, you did it because you're an asshole.' Snape's mouth twitches a bit. 'shit,' Hermione thinks, 'can he hear me? That is so fucking creepy.' Snape's eyebrow goes up. He looks amused.
"Do you have something to tell me, Miss Granger?"
"Uh-" she says, trying to formulate a coherent thought. "You threatened Neville with the death of his toad to impress on him- no all of us- the seriousness of the subject at hand and the potential consequences of our mistakes."
"Correct, Miss Granger. Five points to Griffindor." Hermione's mouth drops open at this. Snape has to restrain himself from rolling his eyes. "Also, I did it because I'm an asshole. Go to bed. You look tired." He exits back into his lab, leaving a very stunned Hermione Granger sitting at his desk, mouth still open.