At the height of the War in 1943 British Intelligence receives a microfilm containing vital information regarding Hitler's so called vengeance weapons, the deadly V-I and V-2 rocket programme being conducted at Peenemunde in northern Germany. A brilliant young French scientist, Jean Giscard, had been forced to join the development project as his family came under ever increasing threats from the Nazis in occupied France. Before the War Giscard had studied at Berlin University, and therefore knew many of the leading scientists now working in Peenemunde, they remembered him well, and requested that he be included to work on the top secret project with them. Horrified at the destructive nature of the weapons he is helping to develop, he tries escape in order to warn the Allies that not only are the lives of thousands of people at risk, but that the weapons could quite literally affect the final outcome of the War against Nazi Germany. After successfully making contact with the Special Operations Executive he is spirited out of northern Germany via an effective underground network to the relative safety of neutral Portugal. Chief Inspector Garvan, on secondment to MI5, finds himself ordered to accompany his British Intelligence colleague, Major Spencer Hall, to neutral Lisbon. Their mission is to escort the Frenchman safely back to England, but it's a race against time, SS Reichsfuhrer Himmler has ordered the Abwehr to track Giscard down and bring him back to Berlin. Unbeknown to Garvan there was another reason for his inclusion on the mission, for Major Spencer Hall has another remit, London suspected that one of their own agents is a traitor and working covertly for Berlin. After arriving in Lisbon, their fears are confirmed when the double-agent divulges the whereabouts of the French scientist to his Nazi spymasters, with bloody and deadly consequences. They then find themselves faced in a desperate race to track down the traitor operating out of Portugal who has fatally compromised not only their mission to Lisbon, but Allied secrets for the future conduct of the War. In their deadly game of smoke and mirrors no-one is ever quite what they seem.