Federal Marshal John Kruger (Arnold Schwarzenegger) is assigned to look after people as part of the Federal Witness Protection System. His latest charge is Lee Cullen (Vanessa L. Williams), a key witness in a case against her employers, the Cyrez Corporation, who are secretly selling their hi-tech weapons to the Russian Mafia. Her safe passage to the courtroom is endangered by corruption within the ranks of Kruger's bosses, which leads to him being framed and thrown off the force.

Hot-shot defence attorney Kevin Lomax (Keanu Reeves) seems to have landed on his feet when he is poached by an international law firm in New York. Lomax is welcomed by the charismatic John Milton (Al Pacino), who seems to take an especially close interest in his young employee's career. Meanwhile, Lomax's wife Mary-Ann (Charlize Theron) suffers a breakdown, believing that she is losing her husband to a dark and powerful force.