"Quarter-inch dices on the rat spleens, Marchbanks! Precise, quarter-inch dices! I suggest you pay more attention to your work if you don't wish to trap more rats yourself and spend the rest of the term in detention dissecting them!" Snape snarled from the open door to the classroom.

I groaned inwardly from behind the lab table, keeping my head down and my eyes on the Pepper-Up potion I was making for Madam Pomfrey. Snape was in a Mood, and I knew there was no reasonable way to calm him once he got going.

He stalked into the lab and slammed the adjoining door closed, robes billowing everywhere.

"Mother of MERLIN!"

Here we go. Snape could cuss for England.

"Of all the lack-witted idiots to darken my classroom doorstep, Marchbanks has to be the worst –"

I smirked into my cauldron, stirring in the ground cayenne. Jolly good, Neville will love to know he's been displaced in the professor's affectionate regard.

"—and most inept since Longbottom! Quarter-inch dices! Is that so difficult to comprehend? There are rulers available for reference in the store cupboard!"

Spoke too soon. Poor Neville. Dear Professor, if Marchbanks is so awful, why didn't you just make him scrub the floor with his toothbrush or something equally disgusting?

"School full of morons, can't trust any of them to do what they're told or to work independently —"

All right now, I quite resent being lumped in with the rest of the unwashed masses at this school!

"— What are their parents teaching them at home? A little hard work never killed anyone! A little attention to detail is all I'm asking. Frigga's splintery broomstick!"

Oooh, that's a new one. I knew I'd learn to brew potions as Snape's assistant, but I never dreamed I'd get such a delicious education in the finer Wizarding curse words. He is really in fine form now, pacing across the flagstone floor of the lab, long-fingered hands gesticulating with every word, his eyes full of passionate fire…

What? No. No, no passionate fire. No long fingered hands. No fine form. I am not going there. I don't care that I haven't been laid since I broke up with Ron over Christmas hols, I am not going to start thinking lascivious thoughts about my TEACHER.

"Can't rely on any of them except for you, Granger!" Snape growled. He seemed rather put out about it, too.

Snape stalked over to inspect the potion in my cauldron. "Your classmates might be able to match you in ability, Miss Granger, but they refuse to apply themselves."

Please, sir, let me apply myself to… No, Hermione, we are Not Going There.

"Why is it, Miss Granger, that you work hard enough for any six people? Have my bad habits… rubbed off on you?"

I whimpered. Rubbed off, indeed. He knows. He somehow knows I had one stray inappropriate thought, and he's going to castigate me for it. I will never live this down.

"Sir, I've been working hard enough for any six people since I was in primary school. It has little to do with you, other than attempting to meet your exacting standards," I replied, firmly tamping down the thoughts rising, unbidden, to the forefront of my mind.

"You exceed my standards, Hermione," he said quietly and walked back to the classroom.

Prompt from pyjamapants:

"Severus is having yet another snarky diatribe. What is Hermione's accompanying mental duet?"