On April 14, 1865, John Wilkes Booth assassinated the 16th President of the United States, Abraham Lincoln, as part of a far-reaching conspiracy.

Director Robert Redford chronicles the aftermath of the killing in this historical courtroom drama, told from the perspective of the one woman arrested and charged for the murder.

John Wilkes Booth (Toby Kebbell) is arrested along with his co-conspirators Samuel Arnold (Jeremy Paul Tuttle), George Atzerodt (John Michael Weatherly), David Herold (Marcus Hester), Lewis Payne (Norman Reedus) and Michael O’Laughlen, as well as Mary Surratt (Robin Wright), who owned the boarding house where the men concocted their heinous plan to slay Lincoln (Gerald Bestrom).

Idealistic lawyer Frederick Aiken (James McAvoy), a protege of former US attorney general Reverdy Johnson (Tom Wilkinson), is hired to defend Surratt against the legal rhetoric of renowned prosecutor, Joseph Holt (Danny Huston).