Will Kiehn is seemingly destined for life as a humble farmer in the Midwest when, having felt a call from God, he travels to the vast North China Plain in the early twentieth century. There he is surprised by love and weds a strong and determined fellow missionary, Katherine. They soon find themselves witnesses to the crumbling of a more than two-thousand-year-old dynasty that plunges the country into decades of civil war. As the couple works to improve the lives of the people of Kuang P'ing Ch'eng - City of Tranquil Light, a place they come to love - and face incredible hardship, will their faith and relationship be enough to sustain them?