"On the eve of the bloody battle of Shiloh, the beautiful wife of an important federal congressman turns up at General Ulysses Grant's headquarters. She demands a pass through the lines to visit her twin sister in Confederate-held Corinth, Mississippi, who she says is in grave danger." "Not wanting to displease the wife of such a powerful politician, Grant reluctantly relents. But he comes to regret it when, after the battle, the sisters are found murdered in a clearing in the woods - both shot in the heart, embalmed, and placed in the same coffin. Perplexed, Grant calls upon U.S. Secret Service agent Harrison Raines, a southerner working for the Union army, to go into Corinth to find out what happened to these poor women and why." And as he prowls the saloons, mansions, and war-time hospitals of the besieged town, Raines begins to discover the reason for the murders - as more killings accrue.