Artillery survey suffered during the pacifist inter-war period but the war in North Africa highlighted its importance. By the end of 1942 ten major survey units had been formed. Nine were conventional serving in all the main theatres, including the Far East. They played a key part in victories such as El Alamein, Anzio, Caen and Imphal, with their flash-spotting, sound-ranging and surveying of gun lines. A tenth regiment was secretly involved tracing the flight of Hitler's V1 and V2 rockets in order to locate their launch bases. These 'soldier-scientists' were all trained at the School of Survey, Larkhill, on Salisbury Plain. Their work took them to the front line and a considerable number were casualties or became POWs. This is the story of the contribution of these 4,000 men who made up the Survey Regiments. It tells of the heroes, such as Robert (Tug) Wilson of the SBS and the skilful men whose actions under the most difficult and dangerous conditions have received little acknowledgement until now.