So, my friends and I woke up in this forest none of us recognize, and were scattered by these wooden dog things. Now I gotta find my friends before we get into any more trouble. Now if only I wasn't a foot tall, and can say more than "Eevee"....
Twilight has theorized the possibility of creating pocket dimensions. Facing the ridicule of the theoretical magic community she has set forth to prove them wrong. She constructs a portal and enters it. Inside, she finds a field of empty white.
After being banished, Nightmare Moon finds she is able to talk with Discord, also sealed away. The two despise one another, but talking with a hated foe is better than endless monotony. Over time, the two fall in love, up until tragedy strikes.
Twilight Sparkle awakens one morning to find all of Ponyville wholly consumed by a spreading cloud of white. Hopefully The Stranger inside her castle can help her understand what this all means.
In the near future mankind was driven into a biochemical war against an unidentifiable contagion created by an asteroid that struck the planet. Without no cure or any form of escape, mankind buried themselves and awaited their extinction.