Description from Google Books:

"From 1979 to 1985, Adolf Tolkachev, an engineer at a military research center, cracked open the secret Soviet military research establishment, using his access to hand over tens of thousands of pages of material about the latest advances in aviation technology, alerting the Americans to possible developments years in the future. He was one of the most productive and valuable spies ever to work for the United States in the four decades of global confrontation with the Soviet Union... Drawing on previously secret documents obtained from the CIA, as well as interviews with participants, Hoffman reveals how the depredations of the Soviet state motivated one man to master the craft of spying against his own nation until he was betrayed to the KGB by a disgruntled former CIA trainee."--Provided by publisher.

Snippet from Google Books:

Drawing on previously secret documents obtained from the CIA, as well as interviews with participants, Hoffman reveals how the depredations of the Soviet state motivated one man to master the craft of spying against his own nation until he ...

Description from Harvard Library:

"From 1979 to 1985, Adolf Tolkachev, an engineer at a military research center, cracked open the secret Soviet military research establishment, using his access to hand over tens of thousands of pages of material about the latest advances in aviation technology, alerting the Americans to possible developments years in the future. He was one of the most productive and valuable spies ever to work for the United States in the four decades of global confrontation with the Soviet Union... Drawing on previously secret documents obtained from the CIA, as well as interviews with participants, Hoffman reveals how the depredations of the Soviet state motivated one man to master the craft of spying against his own nation until he was betrayed to the KGB by a disgruntled former CIA trainee."--Provided by publisher.