The incredible true story of the librarian, the Nazi spy and Ireland's secret role in turning the tide of World War II When unassuming librarian Richard Hayes, a gifted polymath and cryptographer, was drafted by Irish intelligence services to track the movements of a prolific Nazi spy, Hermann Görtz, Dublin became the unlikely venue for one of the most thrilling episodes in Irish history. In a complex game of cat-and-mouse that would wind its way through the city and its suburbs, Code Breaker reveals how Richard Hayes cracked a code that helped turn the tide of World War II, and uncovers a secret history of the capital that has remained hidden in plain view for the past 70 years.