Hermione wandered around Hogwarts one afternoon, bored. Nothing to do, nothing at all; so she decided to go the library; one of her usual hangouts. Being the smartest in her grade, she knew most of the spells already for her NEWTS, but that wasn't what bothered her. No. She wanted to entertain herself somehow. So she wandered down the library hallways, Madam Pince keeping a close watch on her, staring down her hawk-beak of a nose. Hermione found the potions section; where she had found the Polyjuice potion in her second year. She found the booke, Most Potente Potions, and flipped to the page. Ah, the Polyjuice potion. It would be fun to impersonate someone else; she never got to, as the hair she got was not human hair as she thought, but cat hair. This time she wanted to do it right. Just one hour though; and the stuff tasted nasty; having to drink it continually would be a pain in the arse - now she knew what Barty Crouch Jr. suffered impersonating Moody.

She scanned the page, when she saw small print at the bottom that she hadn't seen before: "See page 104 for a similar potion." Hermione eagerly flipped to that page. The Switching Potion was scrawled across the top of the page in spiky script.

"This potion allows the drinker to turn into the form of another. The other will then turn into the drinker for that day. When properly brewed, the potion appears blood-red in colour."

Sounds great, Hermione thought to herself. She ran her finger down the page, scanning the list of ingredients and directions. And it would take only an hour at most; whereas the Polyjuice potion took a month. Hermione smiled and checked the book out of the library, humming to herself.

Hermione walked back to the Great Hall, to find no one there. Typical on a Saturday; everyone was outside. She shrugged and got out her potions ingredients and cauldron, and sat at a table, setting up the cauldron. Hermione flicked her wand causing blue flames to erupt underneath the cauldron. Carefully she read the directions and measured out the ingredients. Hermione finally ladled most of the potion into a goblet she found lying around on the table. There was some spit around the edge, but it was clean enough, Hermione decided in her eagerness, and she raised the goblet to her mouth and drained it. It tasted horrible; extremely acidic, and it seemed to burn at her throat. Hermione looked back at the book and turned pale. Not because of the potion and it's changes taking place already, however.

In her haste, she had neglected to read the last step, "add the other's DNA." Just great, she thought. Using someone else's goblet; there was no telling whose it was; and the spit on the edges had a perfect copy of the person's DNA. True, spit doesn't normally have genetic coding, but as the drinker had a bloody lip, this did.

Immediately, she felt the effects. Her legs and arms grew longer, and her torso expanded. She looked at her hands, and saw them grow larger in size, her fingers lengthen, and the backs of her hands paled.

Hermione groaned, except her voice sounded extremely different. Not a girlish sweet voice anymore, but a deep milky baritone issued from her throat.

"Oh, dear Merlin - " Hermione began, then she was struck dumb. There was something - oddly familiar about that voice. Dully she realized how much taller she was. Then something snapped and she ran to the nearest girl's bathroom outside the Great Hall. Again, thank Merlin no one was there. She looked into the mirror and nearly fainted. A scared-looking Severus Snape looked out at her. Hermione raised her hand slowly to her face and as she prodded her new hook nose, so did Snape. She ran a hand through her hair; it was no longer bushy, but straight, sleek, and greasy; it was like running her hand through a can of motor oil. She blinked and so did her reflection.

Of all the hundreds of people at Hogwarts, why did Snape have to leave his goblet? She thought angrily. She wandered out of the girl's bathroom, hoping she wouldn't run into anyone. That proved false.

She was walking down the hall, when a fuming but familiar voice echoed throughout the hall.

Fuming voice: "Miss Granger!"

Hermione swiveled around; that voice was her old voice, and she found herself looking at her old self.

***********

Severus had been in his dungeon, sitting on his swivel chair behind his desk, grading papers, when he felt it. An odd burning feeling as if he had just downed a potion with physical-changing properties, he thought. He hadn't of course, which was what puzzled him. As he felt his body contort and change, it dawned on him that someone else could have drunk the potion - a simple Switching Potion - of course. A potions master for 14 years, Snape knew his stuff. Interested, he watched his left hand still holding a quill darken to a tan in color, shrink, and his fingers shortened. A muscle twitched in his changing face; he didn't know who would be so stupid as to think of switching bodies with him, and without even consulting him. Snape remembered something, and frantically searched his desk drawers for something; at last he found it. Years ago McGonagall found it amusing to give him a mirror; he didn't think so, and since then the mirror had sat in the back of his bottom drawer, unused. Until now, when Snape brought it out, and looked into it.

Snape's face contorted and twitched with spasms of horror rarely seen on the man's face. As his face twitched, so did the face in the mirror, with its brown eyes, girlish face, and bushy brown hair. Snape winced; why her of all people? He stood up immediately, dropping the quill on his desk, and immediately noticed the difference in height; he felt much shorter, much closer to the ground. He dashed out of his dungeon and down the hall up the steps, his black robes now too long for him and billowing everywhere.

Luckily when he exited the staircase by the Great Hall he saw an all-too familiar back ahead of him; his own. Fuming and shaking with anger, he yelled out "Miss Granger!" and shuddered, hearing such a high-pitched girlish voice come from his mouth, or rather, her mouth, he was just using it. She spun around, and he shuddered seeing his self in a Gryffindor girl's uniform complete with pleated skirt, that was many sizes too small.

Hermione (in Snape's body): "What do you want?"

Snape (in Hermione's body): "I am still your professor, so call me 'professor' or 'sir.' Just because I am in your body and you in mine does not make it otherwise."

Hermione: "How long is this supposed to last, then, professor?"

Snape: "A week, you idiot-girl! And may I ask why - "

Hermione: "I was bored."

Snape: "Why did you want to switch bodies with me, Miss Granger?"

Hermione: "I didn't want to! Next time don't leave your bloody glasses lying around!"

Snape: "Next time don't drink from other people's glasses!"

Hermione sighed exasperatedly, as she looked down at herself, wearing a sour look on her face.

Snape: "This is not my doing, idiot-girl."

Suddenly Snape went quiet, hearing distant footsteps. He put a small hand over Hermione's (his own) mouth, and pulled her towards an empty classroom. Hermione licked his hand over her mouth, not wanting to physically harm her body by biting it or whatever. He cursed and wiped the spit off on the skirt; Hermione's.

Hermione: "Why'd you bring us in here?"

Snape: "Shhh - don't want to be seen. Us being seen together, the supposed Professor Snape in a skirt, you in my robes would give rise to more rumors than we can afford."

Hermione: "Then what do you propose we do?"

Snape: "I'm afraid we have no choice but to impersonate one another."

Hermione: "We couldn't just tell.?"

Snape: "No! Too many questions, aroused suspicions - no, best if no one knows but us."

Hermione took out her wand and flicked it; moments later she stood in Snape's robes, he in her uniform. Snape looked down at the uniform at her robes, and nodded.

Hermione: "The Gryffindor password is Fawkes. Girl's dormitory is on the right, third door."

She almost giggled seeing the look of terror on Snape's face, or her's, rather. However, he quickly regained his composure.

Snape: "My living quarters are through the door to the left of my desk."

Snape left for the door, then turned around as if remembering something.

Snape: "And keep my reputation, will you? I'll strangle you if I so much as hear that you smiled at someone!"

Hermione smiled mischievously, watching Snape turn and leave. This just might turn into an interesting week.

Hermione walked out, determined to act her best as Snape; no smiling, no happiness, no nothing; just sneer at people particularly Gryffindors, and act bitter and nasty. And never take a shower. She walked out of the classroom down a hallway to the dungeons; where she would be spending her week.

She went through the door into Snape's room. Stony just like the rest of the dungeons, and just as dark, with the exception of a few flames lighting it. The bed was some black wood, with black sheets on it. She sat down on the bed and marveled at how soft it was; just from looking at it she thought it'd be harder. Black shelves full of potions and dark arts lined the dungeons. She looked around; nothing interesting. No diary, no teddy bear, no Legolas poster, nothing interesting about their potions professor. But then, what did she expect of Snape?? Hermione left the dungeons to nowhere in particular when she suddenly felt a great urge to pee.

Oh fuck, she thought - oh, fuck. She walked down the corridor to where she knew the bathrooms were. She by instinct went to the women's and opened the door. Parvati saw her pale face surrounded by greasy black hair - Snape's face - and screamed and ran out. Hermione suddenly clapped a hand to her mouth, remembering - she turned and opened the men's bathroom door. No one in there, thank Merlin. She went to the urinals on the side, raised her's - Snape's robes, and then she shuddered. She put her hands on the elastic at her side, and pulled down a pair of black boxers - Snape's. Fighting back a wave of nausea, she groped for the organ she knew to be there, trying not to - look - . Fighting back another wave of nausea - this was Snape's pale body she was in - she held it in her hand, holding up the robe with the other, aimed for the urinal, and peed. Disgusting - never in her life did she think she would be - male, let alone have Snape's body. Just as she pulled the black boxers up and let go of the robe, she barfed. Walking out, she caught a glimpse of Snape's paler-than-usual face looking out at her from the mirror - she gave it the finger before realizing that for the next week, it was her own face. She prodded the hook-nose and left.

Snape was walking to the Gryffindor dormitory, having nothing else to do. Most unfortunately, he ran into the two people he least wanted to see right then - Potter and Weasley.

Harry: "Hey Hermione! Whattup?"

Snape trying to appear cheerful and happy and Hermione-ish: "Hi guys! How are you?"

Ron: "We were just looking for you - you weren't in the library, and Dobby said for once you weren't harassing the house-elves so."

Harry: "Well, you're here now. Anyways, I fell asleep again in Divination, when I dreamed that Voldie came and tortured me and my scar started hurting. I'm scared! What do you think it means?"

Snape: "How should I know?"

Harry: "But you're smart! You usually know this stuff! I'm worried - Hermione! I need support!"

Snape: "Oh, sorry."

Ron: "Where were you anyway? I need help with my potions homework! That son- of-a-bitch slimeball - stupid greasy git."

Harry: "'Wish he'd do us all a favor and go to fuckin' hell!"

Snape was using all his willpower not to appear angry.

Ron: "Ya! Stupid greasy bat - I wouldn't be surprised if he was a death eater."

Harry: "He is. I saw the mark on his arm in my fourth year. We should've known, he's such a fuckin' asshole!"

Snape's/Hermione's face turned livid with anger and hatred - even if he was superb at hiding his feelings, this was too much.

Ron: "What's wrong with you, Hermione? He's not exactly loving toward you either."

Snape: "Leave him alone!"

Harry: "What!?! He's a fuckin' bastard, we all know that - why you protecting him?"

Snape: "I don't care who he is, he saved your life Harry - and he's not a death eater anymore - Dumbledore trusts him."

Ron: "Ya, you think all teachers are saints or something, 'Mione. That's your problem - you're too trusting."

Harry: "Just let her go, will you?"

Ron: "Why? 'Cauz she's your girlfriend now that Cho dumped you?"

Snape felt a jolt - fuck - for the next week he'd have to pretend to be Harry's girlfriend? No... O, Merlin no!

Harry: "Yes. No, her boyfriend is Krum, remember?"

Ron: "Oh, yeah..Heh, sorry, 'Mione."

Snape breathed a sigh of relief.

Snape: "Well you guys, I have to spend some time in the library before dinner - see you then!"

Snape trotted off as Hermione-like as possible. Once he rounded the corner, he gagged and retired to a more normal pace.