Written for Kelly's Decisions, Decisions Competition (Round 5: Whatever type of pairing we wanted; SeverusMarcus; "I wouldn't do that if I were you"; "Some people without brains do an awful lot of talking, don't you think?" -Frank Baum; Fist)

Detention

"I wouldn't do that if I were you." A low, deep voice sounded from directly behind where Marcus was just about to set a dung bomb off in the Charms classroom on a bunch of unsuspecting first years. When he didn't respond, the voice repeated, and a cold hand gripped his shoulder, spinning him around so that he was face-to-face with none other than Professor Severus Snape. His stare was so cold it could have frozen hell.

"Did you not hear me, Flint?" Snape said. "I said that unless you want detention for the next month, I wouldn't do that if I were you."

With the dung bomb still clasped firmly in his hand, Marcus lowered his arm. "Actually, Professor, you never said anything about detention."

Snape scowled, but his gaze didn't leave the seventh year student… not for a second.

"Nor would I have to if you were to set that off." He nodded toward the dung bomb. "No doubt you have heard of detentions with me, Flint?"

From the look in Marcus' eyes, he had very much heard of – and no doubt experienced – detentions with Professor Snape.

"Give it to me." Snape held out his hand and slowly, Marcus handed the dung bomb over. "Detention this evening, Mr Flint," he said. "My office at seven. Don't be late. And just when I thought your brains were growing bigger." He stalked away, leaving an angry-looking Marcus watching after him.

With a scowl and a rather rude gesture to the back of his teacher, Marcus turned in the other direction, deciding not to go to class for that afternoon.

…

"How many lines, sir?" Marcus asked without so much as a hint of remorse in his tone. He was standing on the other side of Snape's desk, the Potions master staring coldly back at him.

"Lines?" he questioned.

"For my detention… sir."

Snape raised an eyebrow, almost amused by such a question. "Mr Flint, when have I ever given lines as a detention? No, you'll be helping me clean all the cauldron bottoms of the first years… by hand."

Nothing Snape had said previously had sparked a reaction from his student, but the mention of no magic got Marcus' fists clenching. In all his years of teaching there was no greater punishment than making a student serve detention without their wand. Lines did nothing but give them a sore wrist.

"Wand, please, Mr Flint." Snape stuck out his hand and waited patiently for Marcus to hand over his wand. For a moment, he thought he wouldn't (a seventh year's attitude to being in detention when they were of age was not always likeable) but seemed to see it best not to argue. With a condemning glare, he passed his willow and dragon heart-string wand to his professor and sighed.

"Where you want me to begin, sir?"

Snape gave a rather cruel sneer, pointing to a rather large group of filthy cauldrons. "They were from this morning and the first years did not have time to clean them. Grab a sponge and a bucket of water, and begin scrubbing. I will let you know when your detention is over."

Without waiting for Marcus' reaction, Snape returned to his marking of third year essays. From the corner of his eye he saw that Flint had not moved. "Every minute standing there is another minute scrubbing," he said coolly.

Scowling, Marcus shuffled from the office and into the Potions classroom. He was muttering under his breath, using words that Minerva would have found very offensive.

…

Severus wasn't sure why he had so many idiots in Slytherin house. They were supposed to be the cunning ones, the dangerous ones, yet as he watched Marcus Flint attempt to scrub the cauldrons clean, he wondered where all that cunning and danger disappeared to. The boy could barely put a sponge to cauldron without thinking too hard.

"Mr Flint, you're free to go." He appeared in the doorway of the classroom, hands clasped behind his back.

Looking more relieved than anything else, Marcus got to his feet and tossed the sponge aside. "Thank you… sir." He gave a scornful look to his professor.

"Thirty cauldrons in four hours, Flint," Severus responded dryly. "My first years can do forty in three hours. For that comment, you will return and complete the remainder twenty-three at the same time tomorrow."

Marcus made to protest. "Sir –"

"Goodnight, Flint. We all need some sleep."

Severus waited as Marcus left the classroom and made his way to the Slytherin common room. When he was sure the boy was gone, he set the cleaned cauldrons aside, shaking his head.

He had once been proud to be a Slytherin, but these days, all that cunning had been replaced with idiotic dunderheads.

So, I'm not going to lie, this was kind of fun to write. Snarky!Severus is kind of amusing.