Red Cross

From publisher blurb:

End of Civilization: A row of short, stubby watchposts marks the edge of civilization, what little there is of civilization out in the wastelands. The Yuli tribe are the only ones fool enough to live out this far and man those towers. But the Yuli never speak to anyone, and do little other than watch the lines of the desert and record things on their stone tablets. Succumb out in the no-man's land beyond their towers and they will do nothing to save you; they merely silently record your passing.

...Only the greatest of fools walk out into the desert beyond those towers. Yet, rumors speak of a land somewhere on the other side of that desert, a land that has not yet been laid to waste. There are many fools willing to try.