When Marie Laure goes blind, aged six, her father builds her a model of their Paris neighbourhood, so she can memorize it with her fingers and then navigate the real streets. But when the Germans occupy Paris, father and daughter flee to Saint-Malo on the Brittany coast, where Marie-Laure’s agoraphobic great uncle lives in a tall, narrow house by the sea wall.

In another world in Germany, an orphan boy, Werner, is enchanted by a crude radio. He becomes a master at building and fixing radios, a talent ultimately makes him a highly specialized tracker of the Resistance. Werner travels through the heart of Hitler Youth to the far-flung outskirts of Russia, and finally into Saint-Malo, where his path converges with Marie-Laure.