Henry and Clara Rathbone were a young couple who sat in the President's box the night of Abraham Lincoln's assassination. Born of socially prominent families and raised as stepbrother and stepsister, the pair began a passionate love affair that thrived despite the wishes of their parents and society. But their witnessing of the event that shook the nation changed their lives forever, leading to guilt, madness, and eventually murder. Relying on historical evidence, Thomas Mallon brings to life one of the most fascinating, though little-known tales from our nation's history, in this astonishing and moving story that is a successful blend of fact and fiction.