After healing the leg of the murderer John Wilkes Booth, responsible for the assassination of President Abraham Lincoln, perpetrated on April 14, 1865, during a performance at Ford's Theatre in Washington; Dr. Samuel A. Mudd, considered part of the atrocious conspiracy, is sentenced to life imprisonment and sent to the sinister Shark Island Prison.
Warner Baxter
as Dr. Samuel Alexander Mudd
Gloria Stuart
as Mrs. Peggy Mudd
Claude Gillingwater
as Colonel Dyer
Arthur Byron
as Mr. Erickson
O. P. Heggie
as Dr. Mac Intyre
Harry Carey
as Commandant
Francis Ford
as Corporal O'Toole
John McGuire
as Lieutenant Lovett
Francis McDonald
as John Wilkes Booth
Douglas Wood
as General Ewing
John Carradine
as Sergeant Rankin
Joyce Kay
as Martha Mudd
