Note: This is purely "fan made" and has no official connection with Somber's Fallout Equestria: Project Horizon story. (It actually has consistency, character development and unlike both FoE and PH; Uses the full extent of the "wasteland" world xP)
You don't have to have read it to read this, but if not, you will likely not understand the whole pre-story concept nor characters.
Anyhow. This is probably my most grim story so far. It contains several cases of male rape, physical abuse and all that "regular nice FoE stuff". It is as said an attempt to be an origin story (or w/e they're called) of P-21. So if you do not want to read about of any of above mentioned, or don't want to read about P-21 getting beat up, molested and humiliated, skitter away now.
Otherwise, if you are interested in reading about these kind of things, the short resume of the story is: It begins on P-21's first day of "work". (althou, he is P-1 at that time) He's in detention/jail for trying to avoid said first day of work. He will meet a total of 3 different mares in this story which will have their go with them. Varying from "totally mentally stable", "caring" and "hey, a fuck toy" in mentality, pretty much.
The second chapter contains some "wrapping up" of the story, as well as a death and slight genital mutilation. (And a "totally happy ending pun".)
And worth noting: This contains more of my "female endowment". To copy paste the explanation from another story: this is something I know pretty much none of you have heard of, and about none have considered, so I'll have to explain it a bit: Female endowment is the size of the vulva overall, mainly the labia. (average length 2-5 cm) How "hung" a female is, is how deep her vagina goes. (average 19 cm) Now, these might first be human standards, but it should give you an insight of comparisons. Now, apply this to a place where females rule with an iron hoof and males are only used as breeding equipment. That might help when trying to make sense of what is being referenced to. That, and everything is actually anatomically accurate, even the slang. At least all I can remember being mentioned and referred too.