Khristo Stoianev is the protagonist of the novel. Although the author sometimes takes the reader into the minds of other characters, the story soon returns to the actions and thoughts of Khristo. As a young man born and raised in the small town of Vidin, Bulgaria, Khristo knows nothing of the world, but he is intelligent and strong. When he is nineteen, Khristo's brother is murdered by fascists. Still reeling from the emotions of this event, Khristo meets a Soviet named Antipin who convinces him to move to Moscow and become a Soviet espionage agent. The young Bulgarian is taught to murder, fight, commit sabotage and perform all acts of a counterintelligence agent. Khristo does as he is told, and keeps his opinions to himself. Khristo excels in espionage work, always placing first or second in any competition. He forms a bond with three other men who train with him, Voluta, Goldman and Kulic, and these bonds last throughout the war.