On the third day of the shelling of Saint-Malo, a stray American shell hits Fort National, where 380 Frenchmen are being held against their will. Nine are killed instantly.

Marie-Laure has lost track of time and does not know how long she has been in the attic. She hears the German officer moving below her. He has been sleeping in her bed. Next, desperate and beginning to hallucinate from thirst, she has a conversation with her father, in which he reminds her not to make noise, lest the German hear her. As the American shelling of the city begins again, she uses the noise as cover to open the first can. It is green beans, which she devours with pleasure.

Werner crawls through the rubble, attempting to position the radio antenna so it will work. Volkheimer insists that they will be killed if they try to use the grenades to blow open the stairwell. Werner calculates how much more power remains in their batteries: about one more day of light and radio. All their food and water are long gone.