January, 1977. While the chief of the CIA's Moscow station fills his gas tank, a stranger drops a note into the car.

In the years that followed, that stranger, Adolf Tolkachev, became one of the West's most valuable spies. At enormous risk Tolkachev and his handlers conducted clandestine meetings across Moscow, using spy cameras, props, and private codes to elude the KGB in its own backyard - until a shocking betrayal put them all at risk.

Drawing on previously classified CIA documents and interviews with first-hand participants, The Billion Dollar Spy is a brilliant feat of reporting and a riveting true story from the final years of the Cold War.