America is at a crossroads. Secession is spreading. And the nation's newly elected president is the target of a conspiracy to assassinate him and trigger a Civil War. The safety of Lincoln and his family--and the future of the American experiment--hinges on the success of a new kind of lawman, known by a word still novel in the culture of the time: detective. But there was only one who would prove to be up to the task--an individual whose extraordinary...