This novel has an "X" shaped plot. One leg follows the life of orphan Werner Pfennig who hopes to escape the poor, short life of a coal miner in western Germany. His quick-minded understanding of radio technology wins entry to a Nazi youth training school. He spends the Second World War pinpointing and destroying clandestine radio transmitters. The other leg of the plot follows the life of Marie-Laure LeBlanc, a blind girl, who thrives in the Museum of Natural History in Paris where her father works. Forced to flee Paris by the invading Germans, the two narratives cross on a late summer day in 1944.