In a remote mountain area of Tennessee, there is a small, virtually unknown town, named Jessup. The inhabitants of this town, the Jessupites, are all descendants of the original Puralist religious movement that settled Jessup in the early 1800's; all save one. Doctor John Roberts has only been a member of the community for the past five years, having moved to Jessup upon the occasion of his grandmother's death. John's grandmother had at one time been a Jessupite but had left the community in disenchantment with the Puralist way of life. What Abigail Wilson Roberts left behind at her demise was a diary that told all about Jessup and the Puralists, and something else that immediately caught John's attention. What he read, in the diary, motivated his move to his grandmother's former home in the mountains of Tennessee. Now that John Roberts had moved into Jessup, the Puralists had a real doctor for the first time in their existence, and along with him came problems the Jessupites never imagined they would ever face. What John Roberts brought with him would test their moral convictions, and, eventually, threaten their very existence.