The main character of the story  is a Japanese spy who disguises himself as a simple, rude Russian officer. The mask of a simpleton and a limited person allows him to gain access to military facilities and obtain necessary information. The sharpness of the plot is enhanced by the fact that one of the characters of the story, the journalist Schavinsky, guesses who is hiding under the guise of a staff captain. But, admiring the courage of the Japanese spy, he does not betray him, but only tries to force a confession.