MI6 agent Aidan Snow rescues a British citizen held captive by Russian insurgents in Ukraine. In the United States, a terrorist attack is thwarted by a man who doesn't even exist. In Russia, a Chechen terrorist escapes from the country's most secure prison. And from Afghanistan, a soldier of the Red Army, long thought to be dead, sends a chilling message: Al-Qaeda is said to possess an RA-115A type atomic bomb, known as a "suitcase bomb." As the connections between these events become clearer, MI6 and the CIA are forced to work together to prevent the world's first act of nuclear terrorism. But where is the weapon, and what is the target? From London to Langley, Virginia, from Afghanistan to Chechnya and into the Caucasus, the chase is on.