1941. Georgy Volkov, Captain of the State Security Service, is delivering to the Soviet Union a consignment of emeralds under a trade agreement between the USSR and Germany. Included in the shipment are a number of top secret documents, the value of which is far higher than any precious stones. The war begins. The train on which Volkov is travelling is attacked by a detachment of Nazis, and he has to flee. He must reach the Soviet side and deliver the important cargo intact as soon as possible. However, a dangerous enemy is hot on his heels - Abwehr agent Konrad von Bützow. The two men will be due to meet on more than one occasion, and soon. The confrontation of these two strong, highly intelligent and worthy opponents is the basis for the plot of the trilogy, "Spies Must Die!"