THE FOURTH MAN: The Hunt for a KGB Spy at the Top of the CIA and the Rise of Putin's Russia

It was one of the Cold War's greatest unsolved mysteries. In the twilight of the Cold War, the CIA and FBI caught three notorious KGB spies. However, rumors had long swirled of another mole. The top-secret search for the "Fourth Man" would lead to shocking implications that reverberate into the present.