Veteran journalist Douglas Waller, who has written ground-breaking intelligence histories, turns his sights on the shadow war of four secret agents for the North, three men and one woman. From the tense days before Abraham Lincoln's inauguration in 1861 to the surrender at Appomattox four years later, Waller delivers a fast-paced narrative of the heroes, and scoundrels, who informed Lincoln's generals on the enemy positions for crucial battles and busted up clandestine Rebel networks.