After being uneasy allies in World War II, the 1950s saw the United States and the Soviet Union entering the Cold War, a thirty-year conflict in which the adversaries never went into physical battle with each other but fought many proxy wars in other nations. This gripping and fast-paced book traces the Cold War through the lens of spying and code breaking by showing how advances in computer technology and mathematics kept the technology race every bit as nerve-racking as the arms race that characterized the conflict.