The stakes are extremely high in an explosive trial when the widow of a gun massacre victim, represented by attorney Wendell Rohr (Dustin Hoffman), sues the gun's powerful manufacturer. Now, with millions of dollars in the balance, 12 jurors must decide if the gun maker was negligent. However, unscrupulous jury consultant Rankin Fitch (Gene Hackman) believes the verdict is too important to be left in the hands of a jury and will spare no expense to ensure the chosen jury remain sympathetic to his client.

Tension mounts and tables are turned as it comes to light that the jury is being manipulated by one of its own, Nicholas Easter (John Cusack), with the aid of a beautiful woman (Rachel Weisz) on the outside to swing the verdict in the direction of the highest bidder...