Everyone thinks they know the story of the Civil War - Four years of America’s bloodiest history; over 600,000 men killed, more than 40,000 men with amputated limbs, and countless more with other injuries. What no one ever asked is "What happened to those disabled men afterwards?"

In July 1864 a Confederate army advances on Washington DC. The North has already sent every able-bodied soldier to Petersburg leaving the Union capital defenseless. Made up of men injured in battle or by disease, these "hopeless cripples" will hold out for a desperate 24 hours until reinforcements arrive. With Abraham Lincoln himself on the ramparts of Fort Stevens, the Invalid Corps cannot afford to fail.