Twelve jurors gather to decide the innocence or guilt of a young girl. Did she stab her uncle in cold blood? Eleven jurors say yes; one, a student actress, says no. The jurors agree to her request to re-enact the crime right there. Props are brought in - including the actual murder weapon. The actress becomes the accused. The foreman takes the part of the murdered man, and as the re-enactment proceeds, some people begin to lose themselves in their parts. It's a tense situation, for if the girl did not kill her uncle - who did? Could it even be one of the characters on stage? The verdict, the solution, and the climax of the play arrive together in a single, smashing conclusion!