Narrated by the only conspirator in the plot to kill Abraham Lincoln who was not killed or executed, Booth tells the story of John Surratt, a young man who falls under the spell of the charismatic and captivating John Wilkes Booth, and is gradually sucked into the vortex of the world-famous stage actor's insidious plans.

The novel opens in 1916, the last year of Surratt's life. Having spent the decades since Lincoln's death as an obscure shipping clerk, Surratt is approached by D.W. Griffith to read from his Civil War diary in Griffith's movie Birth of a Nation. As Surratt begins to read over his diary, the reader is cast back to the tumultuous days of 1864, and a chance encounter between Surratt and Booth.

Booth, whose appetites, fame, and sheer force of will bedazzle everyone around him, helps to secure Surratt a position as the assistant to renowned photographer Alexander Gardner. Over the following weeks, Booth continues to lavish attention on Surratt, slowly drawing him into his web of intrigue.

By the time Surratt discovers the desperate nature of Booth's true intentions, it is too late, and he finds himself caught up in a firestorm of violence that shatters forever his insulated life and modest ambitions.

Based on the historical record, and illustrated with actual photographs of the conspirators and their execution, the novel is filled with nitty-gritty detail of nineteenth-century architecture, photography, Union troop movements, and day-to-day bustle that brings Washington during the Civil war vividly to life.