A/N Of course I should be writing more WUBD, but I have a small case of the block and this just sort of sprang to mind. Hopefully it'll give me inspiration for my other fic… which will be out within a week. This is another challenge response (it's all I seem to write these days), also HG/SS. I'll put the challenge requirements at the end after the story is finished… it will be multiple chapters. Anyway, this is the first part. Tell me what you think!

Chapter One

It was a day like any other, really. Not a particularly auspicious beginning to the day, but then again I don't think I could have coped with any more drama than happened. What was that, exactly? Well you see…

It was my eighteenth birthday, and, up until potions class that day, everything had been going fairly well. The Gryffindors had only, so far, sung Happy Birthday twice, loudly and obnoxiously, and since I knew that there was absolutely no chance of a repeat performance in Professor Snape's class I was fairly content. I was eighteen and officially adult (and if that thought was a little scary I wouldn't admit it to anyone). The best part of the day was, of course, that my best friends seemed finally to have realised that my preference in birthday presents lies towards books, and they had both given me books that looked quite fascinating, really. Ron, of course, couldn't resist slipping one of Fred and George's latest into the box, but I didn't really expect that he wouldn't. So, all in all, it was a fairly pleasant day.

But, of course, that wasn't to be. The goddess of chaos and discord struck (Eris, I believe… not that that's particularly relevant), and did so in a way that would make the next three months hell on earth for me. Yes, it was three months, no, the last two months weren't all that bad and yes, I realise I'm being dramatic. It's called creativity… a dramatical touch lightens up the story. And I do realise I probably shouldn't be having arguments with my (soon to be ex- if he doesn't stop annoying me) fiancé on the paper here, so I'll shut up and get on with the story. Yes, and drop the overly dramatical phrasing. Happy now?

Okay, so…. Ah yes. The potions class. I was working on a solventus potion and, for the most part, minding my own business. Except, of course, when Snape's back was turned and I noticed Neville doing something particularly stupid. I'm not quite sure what he was doing, to be honest, but I do know that whatever he put into that potion would not make a good solventus. So I went over there to sort it out for him (bossy I may be, but believe me if that potion had exploded then there would have been dire consequences… or am I getting ahead of myself?), and, of course, Professor Snape realised what I was doing, stopped sniping at Harry, and came up silently behind Neville and me. He snapped something, probably something along the lines of "What are you doing?" but, knowing Professor Snape, quite possibly far nastier. Poor Neville, though, had absolutely no idea that Professor Snape was right behind him. I don't think I've ever seen him jump quite so high before. Whatever it was he was holding in his hand, and to this day I can't remember what it was, fell into the potion with a loud plop. It began to bubble ominously. Neville, who had a sixth sense about these kinds of things, immediately took cover behind a workbench, as did most of the rest of the class when they saw what was happening. I, on the other hand, was too busy arguing with Professor Snape and losing Gryffindor points when the cauldron exploded. We heard the hissing noises seconds before it happened, and turned as one towards Neville's cauldron. Our arms were touching, I remember that. Difficult not to, really… anyway, then the liquid inside the cauldron exploded all over us and, wouldn't you know it, whatever Neville had managed to come up with was certainly not a solventus potion.

We were drenched in the scalding liquid. I went for my wand, fighting down a scream at the boiling potion coating my entire body. Resisting whatever it was pulling on my left arm I managed to drench myself and Professor Snape in cold water, a blessed relief. Somehow, miraculously (unless it was Neville's peculiar gift for making potions do exactly what they shouldn't), I wasn't burnt at all. Of course, when I turned to make sure Professor Snape was all right, I realised what was pulling on my arm.

"Let go of me at once, Miss Granger!" he snarled, completely ignoring the fact that it was my entire upper arm next to his and there was no possible way I could be voluntarily holding onto his arm. Our sleeves seemed to have fused together and my arm was quite numb.

"I'm not holding onto you!" I shouted back, furious.

Snape took one look at my face and probably realised then that I was telling the truth. He went to our arms and violently ripped the sleeve back. My hand and forearm seemed fine, but when I followed it with my eyes up to my elbow I felt a rush of nausea. Where our arms met, Professor Snape's and mine, at the elbow, they had sort of fused into one arm… and only separated just below my shoulder. I lurched forward, suddenly feeling dizzy as well, and vomited into Neville's mostly-empty cauldron. Snape, with no sympathy whatsoever, was awkwardly shooting spell after spell at our joined arms, arm, I suppose, trying to separate it. Then the numbness wore off and it hurt like hell; it hurt worse than hell, worse than anything I'd ever felt before. I think I was screaming, I know Professor Snape made a low noise, maybe a moan, that was absolutely terrifying. All I could think of was the pain; my nerves were all on fire, it hurt so badly I couldn't see, I couldn't think of anything except the unbearable pain that went on and on and wouldn't stop. The edge of my vision was clouding with it, and then blissfully, mercifully, I fell unconscious.

I woke in the hospital wing with three worried faces peering over at me. Professor Dumbledore's glasses had fallen so far down his nose I thought they would fall on me. Professor McGonagall had a pinched, worried look on her face, and Madame Pomfrey had never looked quite so nervous before. That worried me more than anything else.

"You're awake," Professor McGonagall said thankfully.

"And I wish I wasn't," said a disturbingly familiar deep groan from the left of me. I whipped my head around and, like a bad dream, Professor Snape was to my left. I yanked myself away from him, hating the proximity we were in and instinctively trying to get away. We were still joined at the arm, though, and a fresh wave of pain shot through it at my actions. I screamed and Professor Snape moaned again.

"Stop that!" Madame Pomfrey snapped sharply, looking at me. Then, in a much softer tone, she said, "I'm not sure what you've done to yourselves but it resists every spell I've tried on it. You're stuck, I'm afraid."

At that time my brain had sort of shut down completely and all I could do was giggle hysterically at the horribly bad pun I had just noticed. Then I realised where I was and what was happening and suddenly the situation wasn't so funny anymore. The professors, minus Snape, of course, who was rubbing our arm with his left hand, were all looking at me with concern.

"Sorry…" I mumbled.

"Quite all right, Miss Granger," Dumbledore replied, still looking at me with worry in his eyes. "As Madame Pomfrey has just said, it seems that you two are… somehow… stuck together."

"Then why do we not just unstick one another and finish this?" Snape asked tiredly. He raised his arm, moved mine with it, and glared at me. Slowly and deliberately he continued moving his hand to his face and rubbed the bridge of his nose. My hand was sticking up in the air and I had no idea what to do with it. I felt the sudden urge to cry. 'Blame it on PMS,' I thought, and then thought, 'Oh shit. What if we can't get unstuck? I'll have to deal with… that…' I couldn't even think the word 'tampon' at that stage, 'and Snape and… ohh dear God.' Dumbledore, I suddenly realised, was talking.

"We've tried everything, Severus. All the charms we can think of. The solventus potion; Miss Granger's own, in fact. Nothing works. And I don't know what to do." He sat heavily on the end of the bed, looking, for the first time ever, completely uncertain of himself. We spent the best part of the next hour grilling Dumbledore on everything that had been tried, and he patiently told us after each suggestion that no, it hadn't worked. Finally, frustrated and furious, Snape had had enough. I, of course, had been sitting there timidly not wanting to become involved in the huge argument that was taking place and trying to think of something… anything, really… that would work.

"What can we do, Albus? We can hardly spend the rest of our lives attached at the arm! It's impossible!"

"Severus!" Dumbledore snapped, shocking me yet again that day. "There is nothing," he said slowly and very clearly, "that I can think of to try. You will have to, somehow, find a potion to reverse this. It will be difficult and uncomfortable and you will both have to learn to get along with each other until it is done. It could take a week, it could take a year, it could take a century, but this argument is getting nowhere." With sudden steel in his voice, Dumbledore continued, "You will both leave the infirmary now and decide what you will do. You will have to co-operate until a solution is found. Severus, no taking points from Miss Granger. Miss Granger, you will not purposely antagonise Professor Snape. Is that clear?"

More from shock than anything else, I suspected, Professor Snape nodded in agreement. I nodded too, also quite shocked, to tell the truth.

"Good," Dumbledore said. "Dinner is over, so I shall have the house-elves send food to your rooms, Severus. I shall see both of you at breakfast tomorrow, nine o'clock, if you please. Good evening." And he left! Professor McGonagall, with a last sorrowful glance at me, followed him out, leaving me sitting there alone with Professor Snape.

"This is your fault, Miss Granger," Snape told me.

"It bloody well is not! You were the one who terrified poor Neville into dropping that thing into his potion!" I wasn't quite sure where the new suicidal version of me came from, but I wasn't about to just sit there and let him take his anger out on me.

"If you had not been meddling then I would not have needed to interfere with Neville's potion!"

"He would have blown up the entire school if I hadn't stopped him! You weren't exactly doing anything to help!"

"So you think this situation is preferable?" he snapped.

"At least we're alive!" I shouted at him.

Madame Pomfrey, who had been watching all this, suddenly appeared to have had enough. "Stop!" she shouted, glaring worse than Madame Pince can, which is saying something. "There is obviously nothing wrong with either of you. Out! I will not have you disrupting the other patients!"

Embarrassed, I nodded and tried to get up. Snape apparently did the same on the other side of the bed, because there was a horrible wrenching and I was suddenly flat on my back in the middle of the bed.

"Let's go with your side, Professor," I suggested meekly. Snape, surprisingly, didn't say a word. We sat up together, slowly, and as Snape inched to the left I did the same, until we were both standing next to the bed. I hated the physical proximity; I'm really not a physical person, and forced to be so close to someone, especially Professor Snape, made me extremely uncomfortable.

"We shall go to my rooms, I think," Professor Snape said at last. "We can eat and find a way out of this predicament. Good evening, Madame Pomfrey."

She nodded at us and we left, stumbling and tripping until Snape, glaring at me, told me to walk in time with his steps. Not wanting an argument I merely did what he told me to do. But I wasn't happy… the evening, I knew then and there, would be hell on earth. And of course I wasn't wrong.

A/N II: The solventus came to my mind with surprising ease, which I've suddenly realised probably means I've accidentally stolen it from someone. I don't know who or what but if it's you, please tell me so I can either credit you or change it (or both) … and I think that really is it. R/R!