The 'White Lady' spy net stretched across Europe, encompassing more than 1,000 agents and producing 70 per cent of Allied intelligence on the German forces in the First World War. Through sheer ingenuity, it maintained a staggeringly complex network of spies deep behind enemy lines, who provided vital information on troop movements to and from the Western Front. Its success rested on one man: Henry Landau. Talent-spotted while on a dinner date with one of the secret service's secretaries, Landau left with an exclusive invitation to the service headquarters to meet the legendary 'C' (Mansfield Cumming, the 'chief' of what is now MI6). Fully aware that the man on the other side of the door had a reputation for intimidating his young recruits — such as stabbing his leg without letting on that it was wooden — Landau never expected to be given the daunting task of running La Dame Blanche, nor did he realise how instrumental he would be in helping the Allies turn the tide of the war. Vivid, fast-paced and utterly compelling, The Spy Net is the extraordinary story of the war's most successful intelligence operation, as told by the man who pulled the strings.