A hot, muggy New York City... Twelve white-male jurors try to reach a verdict in a murder trial--a case involving a Puerto Rican teenager from the slums who is accused of knifing his father to death. Eleven jurors agree that the defendant is guilty...but one man, believing the boy is innocent, sets out to convince the other jurors he's right by building a case for acquittal. Based on a television play by Reginald Rose.