At first, no one had been all that worried. Annoyed, maybe, but it wasn't the first time she'd taken off without saying anything. All her friends just assumed she'd gone off to visit her old village, and that was that. She'd be back soon.
After a few days, Headmare Twilight left to check on her. When she came back, she said the ponies in Our Town hadn't seen Counselor Starlight since last month. That's when everyone started to get worried. Word got out. Ponies started to ask around.
It hadn't been until five days had passed that everycreature started looking for her.
Gosh, if only they'd started sooner, they might've been able to find her!
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Hey, everyone! I'm- aw, who cares! This is a contest story! You don't need to know who I am or what I write; all you need to know is that this story was written for the Cozy Glow Short Story Contest #4! This was written for the 'Cozy's got a secret' prompt, and the genre/category is black. Grim. Dark. Awful stuff ahead.
I wrote an entry for... the contest before last, I think, right around the time that I started writing. Now, I'd like to say that I'm probably a bit better at my avocation by this point, but my intrusive thoughts won't let me! I'm gonna do my best, but I don't think I'll be able to top my last submission! 
Afterthought: I procrastinated. I don't think this is as good. Shrug.
Anyways, be suitably warned of the content within this story! Gore, torture, and a heartless little filly doing the most awful things with a smile on her face ahead! I mean it. This is torture for the sheer sake of it.
We're going grimdark, folks! That is: Grim, Dark. Last warning!
Special thanks to an anonymous friend of mine who I like to bounce ideas for short stories off of! My mind's a swirling vortex of entropy, and without their occasional advice, this story would've been a lot blander!
Also, I stole an image from someone named vanillaghosties for the cover.
I would never wanna be left alone with Cozy Glow as she's very manipulative and downright dangerous!!
I'm so in love with this passage, it's paced and framed so well.
You don't get a bunch of stories where Cozy gets to totally go all in for depravity, especially not while keeping her voice so well in tact. Great job with this, I really liked it.
(One mad dasher to the deadline to another, I hope you can got a good rest. I don't think I wanna blitz that much wordcount in a day either.)
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sorry for perpetuating a tired compliment, but I really enjoy Somewhere Only We Know
Aw, what a sweetheart! Thanks for saying so! That compliment means... well, I shouldn't say it means more coming from you since that's a bit ungrateful and ever so slightly presumptuous, but I sure did blush a bit more once I realized who you were!
Erm- anyways, it really is a crying shame there aren't more outright unhinged stories of Cozy Glow doing the absolute worst things. Celestia knows the fandom doesn't shy away from grimdark, but it seems my favorite megalomaniac filly just kind of got... a little skipped over.
Oh, well! The absence of such has helped compel me to make my own!
At least Starlight died a hero.
Now Cozy Glow will suffer next.
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Well, it's easy to wish Cozy would suffer repercussions for her actions, but as it ostensibly stands in this timeline, she doesn't seem to have anything to answer for. Karmically, sure, but even though Twilight is suspicious of her on a surface level, nopony's actually made any definitive link between her and Starlight's disappearance. She's a bit... off, and some ponies may think she's unwell, but otherwise, she's kind, selfless, and helpful to a T.
I don't think anypony would actually blame her for Starlight's disappearance, nor do I think Twilight really thinks she had anything to do with it. She was probably just lashing out, not knowing what else to do in the wake of her former student's tragic and sudden exit. Otherwise, I don't think anyone's even tried to pin the blame on her.
And... it could certainly be said Starlight died heroically. She certainly died obstinately, and what makes a hero if not obstinance? Good deeds? Yeah right.
The exact moral repercussions of her refusal to comply with Cozy's plot... may be a bit murkier than white's good and black's evil. It's hard to say how much Equestria would have suffered if Cozy had succeeded in going back and presumably became an Element of Harmony, but if she does make good on her threat to let Starlight see her friends again, then, well...
...maybe it would have caused less pain to just give in.
Oh, and, by the way, Starlight is my favorite character, too. Just wanted to put that out there in case you thought I might've been hating on her. I love her a whole bunch! To that end, what better way is there to show my love than to have somepony gruesomely torture her and subsequently slander her dying actions? I can't think of one!
In all seriousness, thanks for commenting, and for allowing me to go on my tirade. I'm sure it was just a bit exhausting.
I wonder if any of her friends did find her body? Probably not but its nice to think about