After a Russian train crash, which is followed by a nuclear explosion, the world is on the lookout. The crash is said to have been an accident, but Dr. Julia Kelly (Nicole Kidman), a White House nuclear expert and Colonel Thomas Devoe (George Clooney) with the US Army Special Forces do not believe so. Kelly and Devoe are certain that terrorists are behind the explosion and together they start a high-speed chase that leads them to Eastern Europe. There they get in touch with Devoe’s Russian contacts, in order to quickly find the perpetrators, who seem to be planning another nuclear attack, but on US grounds.