A critique of the American jury system during the McCarthy era, the film tells the story of a jury of twelve men as they deliberate the conviction or acquittal of a teenager charged with murder on the basis of reasonable doubt; disagreement and conflict among the jurors forces them to question their morals and values. It stars an ensemble cast, featuring Henry Fonda, Lee J. Cobb, Ed Begley, E. G. Marshall, and Jack Warden.