AND THEN THERE WERE NONE
A My Little Pony: Friendship is Magic sadfic by mrfatcat.
Listen to this song while reading for best effect: .com/watch?v=mc_VBFu9VLY
An old mare walked alone down the streets of what was once Ponyville. The whole place was deteriorating, the library blackened by a fire caused by lightning. The old mare sighed, remembering better days while walking down the road in front of it, looking for stuff to bring to her home.
The cause of this emptiness started decades ago, when Princess Celestia and her sister Luna, who had ruled along her for five years after being freed from her prison that was the moon, disappeared.
That fateful day started off normal, but the two princesses didn't come from their rooms. When the guards went to look and see why they weren't coming out of their rooms, they found their rooms empty. Nothing was there, both princesses were gone.
In Princess Celestia's room, there was a note. A note with one word, one that ponydom had never heard before.
The word was 'Genesis'.
All the famous pony scholars searched everywhere for what this word meant, but nopony found it anywhere besides that note. And thus, even though the two princesses were missing, life went on, until something strange started happening.
No newborn animals of any kind were born, including ponies.
The population of all the countries in the world turned from growing to declining in a matter of days. Things were fine for a while, until some species of animals became extinct. Eventually, there were no young ponies to replace the old and dying. The graveyards filled up extraordinarily fast everywhere.
Soon, nopony was alive, nopony except one hopeful old mare. She had watched everypony, including her friends, die. It had been years since she had seen a single life form that wasn't a plant or a dragon, which survived due to their diet being water and sunlight, or rocks, respectively.
The mare worked her way through the Everfree Forest to her home, a giant cave on a mountain, where she and her friends had fought a dragon decades ago. As she climbed up the mountain, she thought about how tired she was, and decided to have some flowers for dinner and then go to bed.
That mare was the only pony still alive.
When that mare reached the top of that mountain, she didn't have her regular poison joke tea, which was what was keeping her alive. The plant was playing a joke on nature itself, instead of her. As she climbed into her bed, she was relieved to sink into dreamland, where all her pains would go away.
Her heart stopped beating minutes later, the last of ponydom, dead.
Billions of years later, somewhere close and yet far away, a young girl bounded along the sidewalk to meet with her five friends.