In May 1944, occupied Paris grows harsher as arrests and deportations accelerate and the Resistance faces heightened danger. Isabelle, working under the name Juliette, meets her father at Les Deux Magots and discreetly takes a coil of stolen blank identity papers from his sleeve. He warns her he overheard high-ranking Nazis and SS mention “Nightingale,” and he urges her to rest; Isabelle refuses and admits she has heard little about Vianne except that she is staying cautious to protect Sophie.

That night, Isabelle travels to a Maquis encampment and reunites with Gaëtan after eight months apart. She witnesses an Allied weapons drop by parachute and, inside Gaëtan’s tent, delivers a BBC code message received via Paul: “Long sobs of autumn violins.” Gaëtan immediately understands the urgency and leaves at once for a dangerous operation, and the two part with their familiar, fragile dream of someday living “like lovers.”

In June 1944, a week after the Allied landings in Normandy, Vianne continues hiding Jewish children at the orphanage, now totaling thirteen, as bombing and blackouts exhaust everyone. Von Richter arrives at the orphanage and drags Vianne outside to question her about Henri Navarre, who has been arrested for aiding the enemy. When Vianne begs him not to hurt the children, Von Richter’s reaction turns predatory, and Vianne realizes she has revealed the one leverage that can break her.

Later, in a windowless interrogation room at the town hall, Vianne waits for hours and then faces Von Richter’s escalating threats and sexual intimidation. She maintains that she barely knows Henri and is not helping the Allies, while Von Richter warns he will “hurt” her and the children if she lies, and implies he wants her to be guilty. He ultimately sends her home, promising to continue watching and to punish her if he discovers deception.

That same day, Isabelle leads three Allied airmen—Major Tom Dowd, Major Jack Foley, and Sergeant Smythe—toward the Urrugne safe house, using established signals and spacing to evade checkpoints. At Madame Babineau’s cottage, Isabelle learns supplies are tightening and worries aloud about Gaëtan’s sabotage work, when the sound of an unexpected engine approaches. SS agents burst in, strike Isabelle with a rifle butt, and arrest everyone; Isabelle loses consciousness on the stone floor as the raid closes in on the Nightingale line.