Everything ends. A universally accepted law. If something began, it will finish.
The end of a Fairytale is a happy ending.
The end of a life is normally a sad ending.
The end of the world is... an ending.
Every sapient life form is terrified of "The End". The elimination of everything they knew. The termination of life as they know it. But what actually happens at "The End", what caused it? When will it happen? Who will be there to witness it?
These are the stories of the last things to exist in Equestria. These are the stories of who will be there to see the end.