Intelligence gathering was essential in both world wars, and networks in occupied Belgium were at the heart of MI6's efforts.  In the First World War, agents in La Dame Blanche - the White Lady - acted as couriers, radio operators and spies to undermine and frustrate German control. And then, when war broke out again two decades later, the leaders of that same network regrouped and established a successor; the Clarence Service.

Helen Fry charts the extraordinary achievements of these pivotal groups.  Drawing on recently declassified files, Fry examines who the agents were, how there were recruited, and what impact the information they gathered had on the outcome of both wars.

This is a compelling account of the agents who risked their lives and found ingenious ways to smuggle intelligence out of occupied Europe.