When Hell Struck Twelve - James R. Benn
The fourteenth Billy Boyle WWII mystery takes place in northern France during August of 1944.
Captain Billy Boyle is assigned to track down a French traitor, Bernard Fouch, a member of the French Resistance recently discovered to have been an informer. Fouch betrayed many members of his Resistance group who were subsequently tortured by the Gestapo and then killed or sent to concentration camps. Fouch now has information about an Allied campaign to recapture Paris from the Nazis and he is on the run to tell the Germans. The Resistance is out for blood, and they are hot on Fouch's trail. What they don't know is the plan was leaked on purpose, a ruse devised by a colonel to obscure the Allied army's real intentions to bypass Paris in a race to the German border. Now Billy and Kaz are assigned to the Resistance with orders to not let them capture Fouch: the deception campaign is too important. Playing a delicate game, the chase must be close enough to spur Fouch on and visible enough to insure the Germans trust Fouch's intentions.