How will two ponies survive when a portal to a post-apocalyptic wasteland opens and takes them to the world of humans,where everyone has a hidden motive or desire in the city of sin - and how will their friends and family react when they heard the news. will they ever return to the their own world, or will the wasteland haunt them forever.
(Fallout New Vegas/MLP crossover Fic)

I recommend that before you start reading, that you watch the Fallout New Vegas opening cut scene as it explains the storyline and the factions well, because I jump feet first into the storyline.
FNV cutscene https://www.youtube.com/watch?v=LpNw4BXUHOo

Also a gore warning, swearing warning and some Pinkie-dash in the future