A few short hours after President Lincoln has been assassinated, Dr. Samuel Mudd gives medical treatment to a wounded man who shows up at his door. Mudd has no idea that the president is dead and that he is treating his murderer, John Wilkes Booth. But that doesn't save him when the army posse searching for Booth finds evidence that Booth has been to the doctor's house. Dr. Mudd is arrested for complicity and sentenced to life imprisonment, to be served in the infamous pestilence-ridden Dry Tortugas.