In 1941, British Intelligence analysts cracked the German 'Enigma' code. This undermined the German war effort - but also threw new light on day-by-day events in the Nazi concentration camp system. Between January 1942 and January 1943, encrypted radio communications between those camps and the Berlin headquarters were intercepted and decrypted. Historians have largely ignored the information furnished in these intercepts relating to 'arrivals,' 'departures,' recorded deaths and other events at