France, July 1944: a month after the Allied landings in Normandy and the liberation of Europe is under way. In the Pas-de-Calais, Nathalie Mercier, a young British Special Operations executive secret agent working with the French Resistance, disappears. In London, her husband, Owen Quinn, an officer with Royal Navy Intelligence, discovers the truth about her role in the Allies' sophisticated deception at the heart of D-Day. Appalled but determined, Owen sets off on a perilous hunt through France in search of his wife. With the help of the Resistance he finds Nathalie, but then the bitterness of war and its insatiable appetite for revenge catch up with them in dramatic fashion.

Based on real events of the Second World War, The Best of Our Spies is a thrilling tale of international intrigue, love, deception, and espionage.