I saw the signs. I saw the proof. I should have acted, swallowed my pride, told Celestia it was all my fault. But I was scared. Scared for my title, my freedom. If I wasn't so selfish, Fluttershy would be here with us. But she's not. I stare at the blood sucking creature with her face, and yet not her face. What monster have I allowed to flourish? I feel guilt. I have cost countless ponies lives. Fluttershy included. I have no voice, but I must scream. No one knows I am responsible, but I keep hearing the same sentence over and over again.
Why did you keep hush, Twilight Sparkle?
And to be honest, I don't know.

"Applejack?"
"Yes Twi?"
"I found this book outside the Everfree Forest... It seems to be Apple Bloom's diary."
"Mah sis kept a Diary? Does it say what happened to her?"
"...Yes..."

TheLostNarrator did a fantastic reading of this story some time ago; find it here.
Now with a reading in Finnish, courtesy of DubbiKnight.
And a reading by Lotus Moon.