An espionage agent begins working against his own country for the good of the world in this drama based on a true story. Sergei Grigoriev (Emir Kusturica) is a Soviet intelligence operative who has become deeply disillusioned with life under Communism -- while he believes in the ideals the U.S.S.R. was founded upon, he feels they have been become hopelessly compromised by their current leadership, and that the old government must be brought down for the sake of future generations. With this in mind, Grigoriev strikes up a friendship with Pierre Froment (Guillaume Canet), a French engineer who is living and working in Moscow and has no idea his new pal is a spy. Once Grigoriev has gained Froment's confidence, he begins passing classified documents along to Froment with the understanding that they will then be forwarded to French intelligence. It soon becomes clear that what Grigoriev has to share are American state secrets and classified scientific documents confirming the KGB has been digging deep into U.S. security; when the CIA finds out just how much the Russians know, it sparks an international incident and fierce reprisals against the U.S.S.R.