The Allies' plans for D-Day are systematically being transmitted to the Germans, and Gordon Craigie is told to plug the leaks. When the trail leads to the powerful Sir Edmund Quayle, Craigie knows that he is not up against any ordinary spies - and that he must devise an ingenious method for infiltrating the enemy's tightly-knit organisation.
This book is part of the Department Z Books series and is book #19 in the series.