Fiction based on fact, this a story of the search by the Germans and British to establish how far the other has reached in the development of a jet-engined fighter plane prior to WW2. In UK, the Germans use a dissident South-African-born engineer who lost both parents in the Boer War and harbours a resentment against the British government. Dogged police work eventually exposes him. In Germany, the British lose their experienced agent and are forced to use two reserve officers to fill the gap. The two are discovered by the German Security Forces in the act of taking photographs. They are forced to flee across Germany and France with their information, the Germans in hot pursuit. The German Security operatives have orders to kill them and retrieve the photographs. The Munich Crisis of 1938 with the threat of war causes travel chaos and in part, hinders both sides in the pursuit.