"Vilma tells you yes."

TODAY 1944, in preparation for D-Day, the BBC broadcast into France 306 messages. Buried within them were coded messages for the SOE—Special Operations Executive—and French Resistance.

One message, "Vilma vous dit oui" ("Vilma tells you yes"), was an instruction for the Allied operatives to destroy all German rolling stock on the railway line Angouleme‒Bordeaux.

Another, "Madame dit non" ("Madam says no"), meant for them to bring down all telegraph wires between Caen and Alengon, and between Caen and Évreux.

After D-Day the Maquis (French Resistance fighters often supplied by, and working in coordinated efforts with, the SOE) were dispatched behind battle zones to disrupt German transport and communication. Telephone lines were sabotaged, cutting off from Berlin Wehrmacht officers at the front. The Germans responded by sending couriers to deliver messages and they were ambushed and shot. Bridges were blown, reinforcements were blocked.

Like Stalingrad, Normandy had become a German deathtrap.

This article is taken from Chapter 17 of my upcoming release, CODE NAME LISE: The True Story of the Spy Who Became World War II's Most Highly Decorated Woman (Gallery/Simon & Schuster, Jan. 15, 2019). Pre-order here.