Disclaimer: All of the characters belong to JK Rowling. I'm just going to have my fun with them for a little bit.
This story takes place during Harry's second year. It starts out at breakfast in the Great Hall.
"What class do we have next?" asked Ron through a mouthful of kippers.
"Potions," groaned Harry. "Then Defense Against the Dark Arts and Herbology." Harry took a kipper himself and wolfed it down hungrily. He had just picked up a piece of toast and popped it into his mouth, when he remembered that one of his teeth was very loose and on the verge of falling out. Ow! Harry thought too late, as he bit right into a particularly burnt part. However, Ron and Hermione didn't notice.
"Just great," complained Ron. "Hermione, could you pass over the marmalade?" As Hermione handed it to Ron, she glanced over at the head table, vaguely in the direction of Professor Lockhart.
"He's just fantastic isn't he?" She beamed up at him. "Well, I know our first couple of lessons didn't turn out so well-," she said hastily, seeing the raised eyebrows of Harry and Ron. "-but I think we are really lucky to have a teacher like him."
"Yea," started Ron, "If anybody wants to get attacked by mad pixies again." Hermione threw him a disapproving look and they finished their breakfast in silence. After running back up to Gryffindor Tower to fetch their bags, they made their way down to the cold, unwelcoming dungeons where Professor Snape's classes were held. The Slytherins were already queued up outside the classroom door. Harry caught Malfoy's eye, who sneered back at him.
The door opened, and everyone filed resentfully into the room. "Settle down," commanded Snape, seeming to appear from nowhere. "Today I will be attempting to teach you the correct brewing of a Swelling Solution..."
He riled on, but Harry wasn't listening. He popped a sugar quill in his mouth to suck on while he daydreamed about the hours he could be putting in on the quidditch pitch instead. Oh, what he would give to be anywhere else, even doing some homework, instead of being cooped up in this dismal dungeon all morning. Especially with Snape.
"Now," Snape drawled, " The instructions ..." (he flicked his wand lazily) "... are on the blackboard." They promptly appeared there. "You have an hour. You may begin."
Commotion started, as everybody got all of the necessary ingredients. Harry had no idea what to do, so he watched closley as Hermione gathered all of her materials. As everybody got settled back down and lit their cauldrons, Harry quickly collected up the same items, and got to work.
Time soon went by, and the room began to fill with an orange-tinged smoke.
"You should now be at the last stage of the assignment. Your potion should show no signs of bubbling or fizzing, nor should it be any shade near lilac," Snape called out to the class some forty-five minutes later. Harry peered over at Ron, whose potion had all three of the signs Snape had mentioned; the liquid slopped around inside his cauldron, turning a dark shade of lavender. Hermione's potion of course emitted a perfect orange glow, as expected. Harry hastily read the directions, before Snape could catch him dawdling and insult his pitiful potion in front of everyone.
Stir twice counter clockwise, add a crushed scarab beetle, stir twice counter clockwise, repeat.
Harry did so, his tongue fiddling with his wiggly tooth all the while.
"Oy, Harry," whispered Ron. Giving a nervous glance towards Snape, he continued, "Think you could hand me one of those Jobber things? I sort of over-brewed mine." Harry nodded and passed over a very large and putrid smelling root to Ron, mentally quite grateful to get rid of his spare one. He turned back to read the last sentence in the directions:
Chop Jobberknoll feather until pieces are no larger than fingernail; add it with the dried Billywig (pg. 53) after five minutes.
Distracted with adding his ingredients, Harry pushed his tooth a little too hard with his tongue: the tooth gave an almighty crack as the last root that was attached to his gums ripped, and out fell the tooth into his cauldron, which hissed and sparked dangerously. A moment went by as the first couple seconds of shock washed over him. The newly open spot on his gum began to bleed and Harry quickly put his robes to his mouth. To his amazement, no one had noticed this little bit of excitement. All accept Snape, that is. Harry caught his eye and could tell that he had seen the whole thing. He didn't say anything or get up to scold him, he just sat there with an unreadable expression in his coal black eyes.
Then, all at once, Harry's cauldron began to sputter and hiss as it had done before when his tooth had first fallen in. It emitted multi-coloured smoke, which began to fill the small dungeon rapidly. A very bad smell came from it and the potion rose to the brim of the cauldron, bubbling and turning to a tar-like substance. Harry's eyes opened with horror as the out-of-control potion turned a puke-green colour.
Now people were noticing.
Harry didn't know what to do. He looked pleadingly at Hermione, who wore the same expression. Snape now strode over to his table, his face a mixture of peevishness at the interruption, and - could it be - fear?
Snape twirled his wand in a very complicated manner that Harry was sure even Hermione couldn't do, then shouted and pointed at the cauldron, "Avesco bagot!"
The class waited with bated breath to see what would come of this. Then, in a shower of sparks and wind, Harry's potion disappeared. Snape fixed his eyes on Harry. "Detention, Potter, this Saturday, my office." Harry opened his mouth to object, but then Snape continued: "Not even Longbottom would have been so foolish." Snape sneered. Harry scowled at him, as a embarrassed Neville hung his head. "Class dismissed," Snape announced tersely. Everybody filed out of the dungeons muttering excitedly about what had just happened.
"Harry! What did you do?" Ron asked, once they were out in the entrance hall.
"Tell you later," muttered Harry, because Malfoy was watching them, and he really didn't want to be overheard at that moment. Hermione, who was already headed to their next class, beckoned them toward her and the trio hurried off for Defense Against the Dark Arts.
That night at Gryffindor Tower, Harry told Ron and Hermione about losing his tooth in Potions and how it had accidentally fallen into his cauldron. Hermione was quite interested. "I have heard of a potion like that before. But I can't remember where," she said. "I know I have. I'll have a look in one of the books I've just got out of the library." She ran up to the girls' dormitory. Moments later she came down with an awfully heavy book entitled with bright yellow lettering, Advanced Potions: Grade Seven.
"Grade Seven?" said Ron incredulously.
"Yes, well," started Hermione. "It's very interesting and I think it might have something in here about that potion, Harry." She rifled through the pages for about five minutes, Ron peering over her shoulder. "Got it!" She exclaimed, standing up and banging Ron on in the face.
"Ow!" Ron yelped, rubbing his nose, but Hermione ignored him and turned the book around for Harry to see.
"Right there it says: Patentia Potion is the only other substance in existence that can convert its being to the bystander's abhorrence.'" Harry furrowed his brow, completely lost. "You see Harry, that potion was a type of "copy" of a Boggart. Except that it only lasts for an hour and can only take on about five people."
"What's a Boggart?" asked Harry still completely dumbfounded.
"A shape-shifter," said Hermione simply. "It takes the shape of your worst fear."
Ron's face lit up. "Ooh, I could just guess what Snape's Boggart is!"
Harry began to put two and two together. "So that's why Snape looked so scared when he recognized what the potion was! He didn't want anyone seeing his Boggart! Well come to think of that, who would? Listen Hermione," he said, an idea springing to him. "Does it have the ingredients for the potion in that book?"
"Oh, no, I suppose that would be in the Restricted Section." Hermione raised her eyebrows. "Why would you want it anyway?"
"Well you know, just for safe keeping so if we really need it, we'll have it." Harry reasoned.
"You can do whatever you want, but I'm not helping you with it. In any case, we should be starting our Transfiguration essay," She retorted.
Ron grinned broadly and said, "Just think of the possibilities though, for Snape's Boggart. Or Malfoy's, Ha!"
Ron and Harry spent the rest of the evening conjuring up the most interesting and funny Boggarts for everybody they could think of, until they concluded that Snape's would be a frilly pink dress with patterns of bunnies on it that he could never remove.
Chuckling, the trio made their way to their dormitories. After all the tiring events of the day, Harry was grateful to settle down in his warm, four poster bed. Just before dozing off, he lay thinking. Even though he had detention Saturday night, he imagined that he could live through just one evening with "Silly Frilly Snape."