Hell's Fortress — Michael Wallace

Environmental disaster, war, and government dissolution have plunged the outside world into chaos, leaving the embattled polygamist community of Blister Creek facing a host of dire challenges as their lifesaving resources grow treacherously low. When one of their beloved members gets lost in the desert, Dr. Jacob Christianson agrees to send out an expedition that includes his sister, Eliza. But danger follows the search group, literally: nefarious armed drones hover overhead, ready to strike the rescuers at a moment's notice.

Greater troubles soon arise for Jacob and his followers. Refugees from a now-defunct government camp in Utah are making their way to the compound, demanding food and supplies from the community of dedicated believers. This is the end-of-the-world scenario that Jacob and the rest of Blister Creek's denizens prepared for -- and feared more than anything. Now, Jacob's faith will be tested as he decides between doing what is right…and what is necessary to survive.