A 12-man jury is sent to begin deliberations in the first-degree murder trial of an 18-year-old Latino accused in the stabbing death of his father, where a guilty verdict means an automatic death sentence. The case appears to be open-and-shut: The defendant has a weak alibi; a knife he claimed to have lost is found at the murder scene; and several witnesses either heard screaming, saw the killing or the boy fleeing the scene. Eleven of the jurors immediately vote guilty; only Juror No. 8 (Henry Fonda) casts a not guilty vote. At first Mr. Davis' bases his vote more so for the sake of discussion after all, the jurors must believe beyond a reasonable doubt that the defendant is guilty. As the deliberations unfold, the story quickly becomes a study of the jurors' complex personalities, preconceptions, backgrounds and interactions. That provides the backdrop to Mr. Davis' attempts in convincing the other jurors that a "not guilty" verdict might be appropriate.