June 1864: the Civil War is in its fourth year of bloody conflict with no end in sight. The armies of the North are stalled in ransid trenches, and the re-election of Abraham Lincoln to a second term seems doomed to defeat - a defeat that will set off the call for an end to the conflict, dismembering the Union and continuing slavery. Only one group of volunteers for the Union cause is still eager for battle. Nearly two hundred thousand men of colour have swarmed the recruiting stations and are being mobilized into regiments known as the USCTs, the United States Collared Troops. General Ambrose Burnside, a hard-luck commander, is one of the few generals eager to bring a USCT division into his ranks. He has an ingenious plan to break Fort Pegram, the closest point on the Confederate line defending Petersburg - the last defence of Richmond - by tunnelling forward from the Union position to explode the fort's defences. Burnside needs the USCTs for one desperate rush that just might bring victory. The risks are high. Will Burnside be allowed to proceed or will interference from on high doom his plan to failure? The battleground drama unfolds through the eyes of James Reilly - a friend of Lincoln who has been employed by the president to send back an honest account of the front. In so doing, he befriends an escaped slave and minister of the 28th USCT regiment preparing his comrades for a frontal assault that will either win the war, or result in their annihilation.