There was a silent battle fought between the Allies and the Third Reich during the Second World War – the war of the airwaves. As a radar expert, Jack Nissenthall was at the very heart of the development of radar detection and jamming. From as early as 1936, Jack was involved in the development of radar as part of the team led by Robert Watson-Watt which resulted in the Chain Home system so vital to the RAF’s success during the Battle of Britain. He then found himself as a key member of the British and Canadian forces which undertook the infamous raid on Dieppe in August 1942. His role was to break into the Pourville Radar Station to gain vital intelligence on the new German Freya radar. Though unable to enter the station, Jack was able to cut the site’s telephone cables, which meant the German operators had to communicate by radio. These transmissions were intercepted by listening posts in England, through which much was learned. After returning from Dieppe, Jack continued his vital work on radar. It is Jack’s opinion that while there are countless books on the D-Day landings and the fighting that followed, little attention has been paid to the achievements of radar. In this narrative, Jack gives the reader an insight into the inventiveness of those involved, how they sought answers to the thorny problems of an amphibious attack on heavily defended coast, and how by careful planning, absolute secrecy, ingenuity, collaboration, cunning and deception they achieved what most thought was impossible. As Jack wrote about the Normandy landings, ‘If a miracle occurred on the morning of 6 June 1944, it was one very carefully planned by the Allies. By finding solutions and thoroughly testing their designs they made it happen. At long last I can tell the whole story.’