1864, Washington City. One has to be careful with talk of secession, of Confederate whispers falling on Northern ears. Better to speak only when in the company of the trustworthy, like Mrs. Surratt. A widow who runs a small boardinghouse on H Street, Mary Surratt isn't half as committed to the cause as her son, Johnny. If he's not delivering messages or escorting veiled spies, he's inviting home men like John Wilkes Booth, an actor who is even more charming in person than he is on the stage. But when President Lincoln is killed, the question of what Mary knew becomes more important than anything else. Was she a cold-blooded accomplice? Just how far would she go to help her son?