The article analyzes the system of leitmotifs that individualize various characters in the novel “The Book of Nights” by the modern French writer Sylvia Germain. The research highlights the theoretical aspects of the mythologizing of the novel genre in the 20th century. The signs of a mythical novel and the role of leitmotifs in the plot and composition of the novel, their significance for characterizing personalities are highlighted. To characterize the heroes of the novel, the symbolization in nature and the environment, the combination of life and death, scream and silence, sensual and real, was theoretically revealed and practically analyzed. The use of leitmotifs of color and smell as psycho-emotional stimuli of imagination and memory to strengthen the general vision of key scenes and individualize the characters of the story is artistically evaluated. In this context, much attention is paid to the role of the leitmotif of the number “seven”. Attention is drawn to the relationship to death, which is a constant companion of the Peniel family. The article emphasizes the artistic concept of Sylvie Germain. There is a strong connection between the leitmotifs of the novel “The Book of Nights”, literary traditions and the innovative work of the writer.