After a devastating war between the zebras and the ponies 150 ago the civilization are gone and all the ponies and unicorns are living in stables build by Stable-Tec before the bombs blow. But then a girl named Glowing Star in Stable-83 go outside for no apparent reason and his father go outside also for know if she’s safe and bring her back to the house. But sadly the wastelands don’t care about safe and laugh about it.

I really recommend you to go check before Fallout Equestria by Kkat for a understand a little the back story and the why the war and who are the ministeries.