I've been thinking of this story for a while, but sadly I don't have the time to write it. If you like it, feel free to use the idee.
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Basically five or six friends decide to go camping in the forest, and everything is great. The weather is nice, they are having fun and think it will be a great vacation - until one of them accidentally fall down a small cliff and break his leg. It will be very difficult to get him up, so the others decide to climb down to him and see if they can find another way out of the forest. The going is slow and tiresome, and one by one they start to give up. Night has fallen, scary sounds are heard everywhere (or so they think), and everyone is really tired.
Fortunately, they see a small, abandoned cabin and decide to spend the night there. The next day, one or two will remain with the unlucky friend, and the rest will set off to find help. But all that's tomorrow.
Later that night, they start to talk about old myths and legends to pass time, and one of them mention the old legend about the wishing well. Supposedly it was a well where you toss in a coin and make a wish, and the wish will come true. And as this is an old cabin, there is in fact a well outside. Just for fun, one of them (let's call her Trish) tosses a coin into the well and wishes she could get a promotion from her crappy job as an assistant at a school. No one takes it seriously (including her), so it is mainly for fun.
Skip ahead a few days, and everyone has returned home. Trish is at work as usual, and really hate it. She is more than good enough to be a teacher, but as she lacks any papers and experience, no one wants to even give her a chance.
Or at least, until the headmaster calls her to his office and tells her some bad news. Turns out one of the teachers was in a car accident and was killed. Everyone is in shock including the headmaster, but at the same time the school must go on as usual. There's no need to upset the kids as there is a big test coming up in a few days, and right now they are lacking a teacher. For this reason, Trish is finally given her chance. She takes over the class for now, and if she does a good job, she can keep the job. She is sad the teacher died, but also happy she finally got her promotion. Or at least, until she starts thinking about the incident in the forest. She tossed a coin in the well and made a wish to get a promotion, and wasn't that exactly what happened? She never wanted anyone to get hurt, but the promotion is hers. Of course, it could just be a coincidence.
When she tells her friends about it, they don't take it any more serious than hers. It was a strange coincidence, and that's it. But just to prove how stupid it is, they go back to the cabin and one of the others make a wish of his own. He wants a lot of money (who doesn't?) and tosses in the coin. It's not like that's gonna happen, is it?
Well, it does. A few days later, his parents die in a planecrash, and he inherit all the money as he doesn't have brothers or sisters. He really misses his parents and doesn't even think about the money, but even so, that's two out of two. Two wishes, both came true.
A third person makes a wish, and say he wants a better car. A few days later, a drunk driver slams into his car, and he ends up in the hospital for three weeks. Fortunately the insurance company realize it wasn't his fault and pay him the insurance money so he can get a new car - and he can suddenly afford a better car, just like he wished for.
That's three out of three wishes coming true, and all of them in a bad way. Is it still just coincidences, or could there be more too it than that? The friends start to suspect there might be something to the legend of the wishing well, and not in a good way. The well is really powerful and needs to be destroyed before anyone else gets hurt, but at the same time they wonder what really is going on with the well? Is it magical? Is it a demon? Cursed or blessed? And besides, if the well really does make your wish come true, is it worth paying the price? And how far can they go before the wishes really start to get out of hand? Can they destroy the well?
Should they destroy the well? If it really can do anything, can it do nice things like finding a cure for cancer or restore peace in the world? And again, if it can do things like that, is it worth paying the price?
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That's about all i have so far, but it should get you started.
