The New York Times bestselling author of Dark Invasion and The Last Goodnight once again illuminates the lives of little-known individuals who played a significant role in America’s history as he chronicles the incredible true story of a critical, recently declassified counterintelligence mission and two remarkable agents whose story has been called "the greatest secret of the Cold War."In 1946, genius linguist and codebreaker Meredith Gardner discovered that the KGB was running an extensive network of strategically placed spies inside the United States, whose goal was to infiltrate American intelligence and steal the nation’s military and atomic secrets. Over the course of the next decade, he and young FBI supervisor Bob Lamphere worked together on Venona, a top-secret mission to uncover the Soviet agents and protect the Holy Grail of Cold War espionage—the atomic bomb.Opposites in nearly every way, Lamphere and Gardner relentlessly followed a trail of clues that helped them identify and take down these Soviet agents one by one, including Julius and Ethel Rosenberg. But at the center of this spy ring, seemingly beyond the American agents’ grasp, was the mysterious master spy who pulled the strings of the KGB’s extensive campaign, dubbed Operation Enormoz by Russian Intelligence headquarters. Lamphere and Gardner began to suspect that a mole buried deep in the American intelligence community was feeding Moscow Center information on Venona. They raced to unmask the traitor and prevent the Soviets from fulfilling Soviet Premier Nikita Khrushchev’s threat: "We shall bury you!"A breathtaking chapter of American history and a page-turning mystery that plays out against the tense, life-and-death gamesmanship of the Cold War, this twisting thriller begins at the end of World War II and leads all the way to the execution of the Rosenbergs—a result that haunted both Gardner and Lamphere to the end of their lives.