Tom Cruise returns as Ethan Hunt, an operative for the top-secret government agency IMF (Impossible Missions Force). Fellow agent Sean Ambrose (Dougray Scott) has gone rogue, stealing a sample of a deadly synthetic virus named Chimera that could rapidly wipe out the world's population. Ambrose's plan is to sell Chimera to the highest bidder in exchange for shares of stock in the winner's company. Summoned by the new IMF chief (Anthony Hopkins in an uncredited cameo role), Ethan is assigned to recruit the help of Ambrose's former lover Nyah Nordoff-Hall (Thandie Newton), a gorgeous woman who left Ambrose broken-hearted and who may be able to quickly regain his confidence. Once he meets and spends a night with Nyah, however, Ethan is smitten, and now must both capture Ambrose and keep Nyah alive as she infiltrates a nest of vipers. Sophisticated disguises, gun battles, and high-speed chases are the order of the day, very much in the James Bond mold.