When John Pope, a fundamentalist preacher, and his friend Mark, a physician, get into an argument about religion and science, John wishes that science didn't exist. The next day, John somehow finds himself in a world that shuns science and is governed by very strong fundamentalist religious beliefs.
John's adventures take him through this oddly familiar land in a state of intermittent war between several religions. He discovers that his basic understanding of science gives him the ability to survive and prosper in this medieval world. After losing his family, John again finds love, and through the use of science, he saves his faith and his home. At the peak of prestige and power, those who share John's faith persecute him for enlightening others as to the achievements of science. But will John's punishment be carried out before he can find a way to return to the present?