April 1865: The Civil War is all but over after Lee’s surrender at Appomattox, but there are those who don’t want the killing to end. Abraham Lincoln’s assassin is still in hiding—but more violence is planned in a conspiracy to destroy the country once and for all.   With the nation and countless civilian lives at stake, Col. Alphonso Clay, a master of intrigue and detection who has served General Grant with honor, is assigned to the case by the secretary of state. With the help of a beautiful agent, he is about to travel into the destructive heart of a secretive cult older than the United States itself . . .