After six days of proceedings, the trial of a young Puerto Rican man accused of murdering his father and facing execution by electric chair comes to an end. The twelve jurors retire and must now reach a unanimous verdict. For eleven of them, the case is clear, only juror no. 8 (Henry Fonda) has doubts about the guilt of the accused. A heated discussion ensues, and slowly other jury members are no longer quite sure either. In his first film, Lumet stages a thrilling chamber play about the heart of the American justice system: the jury. The camera circles around the great acting ensemble in its search for the truth. Set during the McCarthy era, when the US justice system, and with it American democracy, was shaken to its foundations, the film is a passionate appeal for civil courage and justice.