Casting Off — Hugh Howey

The silo has appointed a new sheriff. Her name is Juliette, and she comes not from the shadows of deputies, but from the depths of the down deep.

But what does being a mechanic have to do with upholding the law? And how will she be able to concentrate on the silo's future when she is surrounded by the ghosts of its past?

Before she can even settle in, the whirring gears of the silo begin to grind anew. Things aren't right. And the people whose help she needs the most are gone.

If Juliette isn't careful, she'll soon be among them.