The Talbot Odyssey Nelson De Mille

For forty years Western intelligence agents have known a terrible secret: the Russians have a mole -- code name Talbot -- inside the CIA. At first, Talbot is suspected of killing European agents.
Then a street-smart ex-cop uncovers a storm of espionage and murder on the streets of New York, while in a Long Island suburb a civic demonstration against the Russian mission masks a desperate duel of nerves and wits. Engineered by Talbot, a shadow world of deception and deceit is spilling onto the streets . . .