I'll be honest with you, I didn't like this at all. I thought this was quite random and rushed, simply because your ideas (although they do draw parallels to bullying and why a person would want to start a high school massacre) are too superficial.
If you want to improve this, then you need to focus more on Maureen as a character. Why is she so vulnerable to being bullied? Is it because she does things which are downright weird? Is it because of her eccentric behaviour? Why would Maureen write such a thing in her notebook?
Really, I think you are capable of making use of your 500 word limit to characterize at least Maureen further. You should get rid of most of the dialogue in this and get to the point. Most of it is really just filler that drags the story along. If you are going to rewrite this, then you should lay the smack on Maureen straight up. And please, none of this primary school playground type of dialogue. Use more aggressive language (I can't tell you what to use exactly as I'll be bending the rules lol).
Some of your other ideas need more work. For example, where the heck is Cold Stone Creamery? Describe the place for me (I'm a clueness New Zealander here). Show important of it that will help me have a better understanding as to why Clara and Kevin would go to such a place as well as nerds like Maureen (as you've put it). Expand more on Maureen's reaction as she had her notebook taken. I mean she pretty much did nothing. I had the feeling that she would be all crazy on them. Who are Clara and Kevin, are they like popular students in their school and like to bully lesser students to maintain their rep? Make that more evident.
Hope this has helped somewhat.
Andy.
"To the edge of the universe and back. Endure and survive."
First off, you said that you still had another 200 words or something like that right? So what I recommend is adding a little detail into the story. Right now it's just kind of bare bones, which it's okay...but I think if you added a tad more detail it would be great, because right now it's just sort of "They go do this, they go do that." Which is okay, but it's always better if you put in some detail, especially in a story this short since it doesn't really have a meaning.
"I'd rather be hated for being who I am, then loved for who I'm not."
So I thought this was a neat, creepy idea. o_O You built up Maureen's character very well without hardly ever having her interact with the MCs. Well done! So the evil laugh thing at the end was very odd, just as I'm sure it should've been. Your dialogue with the MCs when whey were mocking Maureen were well done too, I thought.
The creepy tone wasn't really there though! Or any tone, for that matter. Description was lacking, and thus the tone wasn't really anywhere. This was run completely by dialogue, but I don't think the dialogue can do this alone. That, or they need a lot more monologues. In fact, it would need a lot of focus on the dialogue, if you plan to tell the story with just dialogue. Otherwise, we gotta beef up the description a lot. And I suggest getting into Clara's head because she's the one person who still cares for Maureen. We could see her curiosity, sympathy, confusion, and whatever emotion you can think of. Right now, she's just kind of hanging.
And this "hanging" could be caused by the number of characters you have. With five main characters and little time to tell the story, it can get confusing fast, especially without that description. So.. that's pretty much my only suggestion. Beef up that description! The characters could use more character, and the tone needs more tone! (how's that for simplicity? >_>)
So I mentioned the characters need more character, and it's true because they all seem flat. With only dialogue helping you out, you'll need them to talk a lot more, like I mentioned before. The only character with some life is probably Clara because you showed us her view on the situation fairly well (could be a lot better), but the other three seemed like flat, stereotypical bullies; and then Maureen could use some more build-up to her creepy laugh. It should be surprising for her character, right? So show us some more how sweet of a character she seemed to be. (And then a little more details on the notebook she had, ja? To make it seem more worrisome than the bullies are giving Maureen credit for, and bullies aren't usually the characters readers trust for information.)
The beginning and end also need beefing up, but that goes back to description. Though in the beginning, with the two lovebirds saying "I love you," I'd chop off the he said/she saids because that just ruins the moment. Again, it helps set a tone. In this case, the dialogue tags just make it sound clunky and get in the way when really, we should be feeling disgust like the other two MCs watching them regurgitate love all over each other.
Even flash fiction gets some description to help tell the story. Otherwise, I think you've got a great idea. And your concept teenager dialogue is pretty good too! Just gotta word it a bit more naturally. Though it'll probably change anyway as you add some meat to your story.
