"The Holocaust Codes" unveils the riveting untold narrative of British and Allied codebreakers infiltrating SS and Gestapo messages during the Holocaust, and the Germans' counter-use of cryptanalysis to mask their atrocities against Europe's Jews.

The book centers on the contrasting figures of Nigel De Grey, an unassuming British codebreaker at Bletchley Park, and SS Major Hermann Hoefle, an Austrian loyalist of Himmler overseeing mass extermination. Amid the backdrop of a war waged through electronic intelligence, De Grey, often dubbed 'The Dormouse,' leads Bletchley Park's decryption efforts from 1941 to 1945.

Hoefle, orchestrating heinous operations in Poland, deploys complex codes to cloak the horrifying reality of the camps he oversees, fully aware of potential Allied interception. The narrative spans massacres in Ukraine, the Baltic states, the Warsaw Ghetto, and Auschwitz, exploring De Grey's struggles to convey critical information to leaders like Winston Churchill and President Franklin D. Roosevelt. Collaboration with global intelligence experts and double-agents inside Nazi Germany further unfolds.

The book delves into the alarming indifference of key British officials to intelligence reports on the Final Solution, hindering effective Allied intervention. Post-war, the fate of Holocaust signals becomes a contentious issue, with debates over evidence at Nuremberg, intentional destruction, loss, archival, and concealment.

As the Cold War emerges, the book concludes with a surprising resolution to the fate of De Grey and Hoefle, delivering justice in an unexpected and dramatic fashion. "The Holocaust Codes" is a poignant exploration of wartime secrecy, intelligence, and the enduring legacy of the Final Solution.