The Virginia Peninsula campaign of 1862 serves as backdrop for Monfredo's latest Seneca Falls mystery, a smooth blend of romance, history and suspense, though familiarity with the previous book in the series, Sisters of Cain (2000), is essential to a full understanding of the action here. Series heroine Bronwen Llyr, a Union spy, faces the challenge of saving her brother, Seth, after he's captured by Confederates and confined in Richmond's notorious Libby Prison. Recognized as Bronwen's brother, he's accused of spying and sentenced to hang. Seth's attempted rescue forms the spine of the plot, which also hinges on the safe movement of English tobacco from Richmond warehouses. In the meantime, the other Llyr sister, Kathryn, a nurse in the Sanitary Commission assigned to the Union army, goes about her grisly duties in field hospitals where amputations are almost the only surgery. As the sisters move through the ubiquitous mud between Union and Confederate territory, they encounter various historical figures, both major and minor, who add to the authentic background. The author tends to simplify the business of spying, and her pacing can be uneven in particular, she crowds too much into the novel's final 50 pages (in which the resourceful Bronwen's ability to throw a knife from a distance to pin an assailant's arm comes in handy). But if there are some hasty explanations and unresolved issues at the end, Monfredo's fans can look forward to further enlightenment in the next installment of this generally well-crafted series with a provocative feminist take on the Civil War era.