Saddlebag preacher Thaddeus Lewis uncovers murder and conspiracy in Northumberland County. A body is discovered on an isolated island in Rice Lake. Saddlebag preacher Thaddeus Lewis is sent on a desperate hunt for the truth when a woman for whom he feels a guilty attraction stands accused of the murder. Meanwhile, railway mania grips the county: everyone expects to get rich off the Cobourg–Peterborough rail line — some at the expense of others. Aided by his fifteen-year-old granddaughter and a charming but inexperienced lawyer, Thaddeus defends the woman while privately questioning his motives for doing so. With little hard evidence to go on, the courtroom battle to prove the woman’s innocence seems doomed — until a startling discovery gives the case a fighting chance. But the trio’s digging uncovers a conspiracy that could threaten the future of the entire district. With the fortunes of the county, and his own future, on the line, Thaddeus struggles against shady characters and his own conscience to solve the crime.