Jeffrey Wigand (RUSSELL CROWE) has just been fired from his job at Brown & Williamson, the nation's third largest cigarette manufacturer, by its chairman, Thomas Sandefur (MICHAEL GAMBON), for blowing the whistle on some of their questionable business and research practices.
Lowell Bergman (AL PACINO) is an ambitious producer for the CBS news program, "60 Minutes." Having worked with journalist Mike Wallace (CHRISTOPHER PLUMMER) for fourteen years, Bergman is the best at what he does. When he receives a package concerning product safety studies at another tobacco company, Bergman contacts Wigand, hoping to hire him as a temporary consultant for a possible "60 Minutes" segment.
Wigand is reluctant, however, since such activity would violate a confidentiality agreement he signed with B&W. Doing so would thus jeopardize his severance package that currently provides for him, his wife Liane (DIANE VENORA), and their two young girls, Barbara (HALLIE KATE EISENBERG) and Deborah (RENEE OLSTEAD), the latter of whom needs medical insurance to cover her severe asthma.
When Sandefur threatens to cut off Wigand's severance package if he doesn't sign a completely restrictive supplement to the confidentiality agreement, the former Vice President of research loses his cool, storms out and contacts Bergman, telling him he'll do his story. However, the seasoned producer, sensing far more of a story with Wigand, decides to pursue whatever he knows that's making the B&W executives so nervous.
Taping an interview with Wallace, Wigand details information that might seriously damage not only B&W, but the other tobacco giants as well. Sensing this and in retaliation, they start putting pressure on him by attempting to dig up any past secrets, smear his name and reputation, or simply intimidate him into stopping.
As the stakes increase and Wigand testifies in court against the tobacco industry for Mississippi activists Richard Scruggs (COLM FEORE) and Ron Motley (BRUCE McGILL), he finds his life quickly unraveling with his wife starting to succumb to the unrelenting stress.
At the same time, Bergman suddenly finds his story in danger of not being aired. Meeting with "60 Minutes" executive producer Don Hewitt (PHILIP BAKER HALL), and CBS corporate executives Eric Kluster (STEPHEN TOBOLOWSKY) and Helen Caperelli (GINA GERSHON), Bergman discovers that the network could be sued for helping break Wigand's confidentiality agreement. With pressure mounting from all sides, Bergman does what he can to make sure his story airs while Wigand must decide how far he's willing to go to tell the truth.