The Prisoner of Shark Island

When John Wilkes Booth shows up at the home of Dr. Samuel Mudd (Warner Baxter) with a broken leg, Mudd treats the man, having no idea that Booth has just murdered President Lincoln. But the physician, a Confederate sympathizer, is implicated in the killing, and is sentenced to life at Shark Island, a brutal penitentiary. Despite the harsh environment and abuse he suffers from Sergeant Rankin (John Carradine), when Yellow Fever strikes inside the prison, Mudd's heroic effort to combat the disease causes his accusers to rethink their condemnation of the doctor. (official distributor synopsis)