Bishop Howard Chandler has assigned Pastor Arthur Blake to investigate the burning of a church in the small city of Amboy, Illinois. He learns from that church's pastor that she had to overcome past improprieties by former members. During the investigation of the fire's cause, Arthur and the other state fire investigators uncover disturbing aspects of the ninety-year-old church's design and history. Arthur calls on his federal associates for assistance, as the investigation of a local church fire expands to seeking solutions to related crimes occurring from the present, to recent years, and back to the Prohibition Era. Progress in the investigation intertwines with new developments in Arthur's family life.