Written for Vicky199416's 'happiest time of their life' competiton.

Snape felt a slight feeling of satisfaction as he looked around his second year class, at the equipment on the desk at the back and the students sitting neatly, if apprehensively at their desks.

Practical time.

So much nicer than the theory lessons.

"Today you will be doing your first practical lesson of the year, in the hopes that the summer holidays will not have driven everything you learnt last year out of your heads in time for next Thursday's assessed practical lesson." He noticed a few of the students groan silently; apparently they also felt that the summer holidays had managed to drive every rational thought out of their heads.

Tapping the board at the front of the room with his wand, the pre-written instructions appeared and Snape turned back to his class.

"All the equipment you will need is at the back of the room, supplies in the Supply Cupboard. You have the rest of the afternoon."

Immediately all of the students save one leapt up from their seats and ran to the back of the room to get the equipment they needed and to make sure they weren't left with the older ingredients. One of the students remained in her seat, however, staring at the board with a slightly vacant expression.

"To start the practical you will need ingredients and equipment, Miss Tonks," he remarked as he pulled a stack of sixth year papers towards him. The girl started. Clearly she hadn't realised that the lesson had started and she had been abandoned by her class mates.

"Yes, Sir."

As she headed to the back of the classroom Snape looked down at the top paper of the stack, then wished that he hadn't.

If he had been the sort of person to easily cry he would have been tempted to do so now. The word illegible didn't really cover the mess that covered the parchment and, to be honest, it could quite easily have been invented because of the mess on the parchment.

If he squinted he could make out the occasional letter here and there and, in one place, a whole word. Unfortunately the word itself didn't particularly enlighten him on the essay subject: 'and'. That was the word he thought he might be able to make out. 'And'. Not particularly helpful in explaining to him why bezoars were the antidote to many known poisons.

Giving the essay up as an extremely bad job he marked it with a T and moved onto the next from the towering pile next to him.

Around him the students worked busily in silence, knowing that he would not allow any talking in a practical lesson.

Slowly he became aware of a noxious smell that was permeating the classroom. Cautiously he sniffed the air and half chocked, half coughed as the nauseating smell hit the back of his throat. it was the sort of smell that even managed to taste vile.

Standing up he made his way through the gagging students to where the smell was strongest and found himself next to an unattended cauldron that rested on a tripod and gauze over a flame.

"Whose cauldron is this?"

Everybody in the class turned around to stare at the offending article.

"It's mine, Sir," said Tonks from behind him, her hands full of rat tails.

"You, out of the entire class, seem to have managed to pick a gauze that is covered in something which is gassing the rest of us. Choose another and carry on."

Tonks' hair turned a mousey colour from embarrassment as she tried to avoid the stares of the rest of the class.

"Yes, Sir."

"Now."

"Yes, Sir."

Sitting back down at his desk he pulled another essay towards him and fervently hoped that that would be the worst problem of the lesson. You could never quite tell what was going to happen in a Second Year potions class.

OoOoO

An hour later he had finished marking the rest of the papers and looked up.

"Your potion should have finished simmering for 4 minutes by now so move onto the next set of instructions." He tapped the board and the previous set of instructions were replaced by a new set, carrying on from where the last set had ended.

In the front row he could see Tonks looking slightly panicky, but she seemed to be following the first instruction on the board so he ignored it and carried on.

The noise of students finishing their potions filled the air as Snape walked around the classroom, pausing to check each cauldron's contents and point out ways in which the potion could have been perfected. He had reached the last desk and was inspecting one of the cauldrons contents (which was much closer to perfect than most of the others) when he heard a small voice pipe up next to him.

"Sir."

"Would you please wait your turn Miss Tonks?"

"But sir."

"Five points from Hufflepuff for interrupting a second time in a row. Now will you please wait your turn!" Tonks subsided and Snape turned back to the Ravenclaw whose potion he was inspecting.

A moment later an even worse smell (if that were possible) than the one which he had smelt earlier hit him and he spun around to see what on earth could be causing such noxiousness. To say that it was worse than the smell before was like saying black robes were better than orange. A complete and utter understatement.

Behind him there was a thump as the Ravenclaw girl he had been talking too passed out from the smell.

In front of him Tonks was standing, looking as small as possible behind a cauldron in which something was bubbling. However, it certainly wasn't the potion that it should have been - it was, in fact, like nothing he had ever seen before and he had seen many different variations on the potion gone wrong theme during the three years in which he had been teaching.

It looked like some organic matter had been left in there for several months and had turned into a half dead fungi of some description. It was a greeny-yellow gunge that had some kind of brown scum crusting in spots on the surface. What was even worse, if possible, was the fact that the quantity seemed to be multiplying by the second and was now in the process of boiling over the side of the cauldron.

"Evansco!" The mess inside the cauldron vanished, along with the putrid rotting smell and Tonks was left standing in front of an empty cauldron, facing the wrath of Snape.

"I think I added the wrong ingredients, professor," she said by way of a very weak explanation.

"Clearly not." Snape felt like spitting, he was so angry. "What ingredients did you use?"

She quailed. "I don't remember, Sir."

Snape shut his eyes briefly. He really could have done without this today.

"Clear the rest of this mess up and stay behind after the lesson," he said turning back to his desk. "The rest of you put a sample of your potion into a flask and leave it on my desk."

The class scurried about, putting the potion into flasks and labelling them clearly. One by one they filed up to the front of the room to place the flasks at the front of the classroom.

Eventually there was only Tonks left, standing sheepishly in front of his desk.

"What exactly did you do, apart from not add the right ingredients," he asked after she had stood there for a moment. He was relatively confident that adding the wrong ingredients would not, could not, have resulted in such an end product. Most students over the years had added the wrong ingredients to this particular potion but he had never seen such a reaction before.

She winced. "I didn't follow the last two steps on the first page of instructions," she whispered.

"And why was that?"

"You wiped them off the board before I could finish them."

Now that she mentioned it, he could remember the panicky look she had worn as he had removed the instructions. So it was partially his fault as well.

The realisation did not improve his mood.

He didn't bother asking why she had not said something, it wasn't worth the answer she would give.

"You will write out the instructions for the potion three times, to be handed in next lesson."

Tonks looked pathetically grateful that she hadn't received a detention. Nodding she turned to go, but stumbled as her foot caught the table leg and banged into the desk. The impact knocked over the flasks of potion that were on his desk and the contents flooded over his table, drenching the papers he had been marking for the last few hours.

One glance at his furious face and Tonks was gone, fleeing the classroom whilst her maddened professor was still inarticulate with rage.

Chocking down several insults he would dearly have loved to hurl after her, he gingerly picked up the essays. Not one of them now contained a readable word; the ink was smudged and the parchment slowly disintegrating as the potion sank into it.

Snape slumped back in his chair, dropping the essays back onto his desk - they were beyond redeemable now - and closed his eyes as tightly shut as they would go.

This birthday had been even worse than the previous, and that was saying something.