Colonel Warlemont’s dog, Zipper, becomes ill after eating an entire cake given to them by their neighbor, Miss Hobert. Shortly after, the Colonel receives an unexpected visit from his old friend Harry. Harry reveals that he has married Masha and they are now living in Paris. He explains that Masha works as a seamstress for the wives of powerful men in Paris, allowing Harry to gather intelligence from what she overhears.

Harry asks the Colonel to join a resistance network he is building to help people escape occupied territory. He mentions he plans to eventually send Masha to safety at a farm through this network. The Colonel, knowing Harry has a history of poor judgment when it comes to trusting people, is hesitant. He agrees to think about the proposition, and Harry tells him he will return in a month for an answer.

Leo is on a train in the United Kingdom, concealing from his wife, Sophia, that their son Julian has joined the military. He reflects on Wittgenstein’s Tractatus, disagreeing with its premise and arguing that reality aspires to the ideal of art, not the other way around. He also has a vivid dream-like vision in which he is one of the Turks who have captured Athens and are gutting the Parthenon’s columns for lead. In the vision, the Greeks give the Turks bullets in exchange for a promise to stop destroying the monument.

Leo is overseeing a secret project to move a museum’s art collection into a slate quarry in Wales for safekeeping. The move was prompted after a drunken baron, in whose castle some paintings were stored, had a collision with one of his dogs that nearly ripped a hole in a priceless canvas. While touring the mine, Leo has a vision of his friend, the painter Paul Delvaux, filling the quarry with images of skeletons. He recalls a past conversation with Charlotte about a Delvaux painting, in which she perceptively noted that two figures in different planes of the painting were the same person. Troubled by his increasing difficulty in separating dreams from waking life, Leo finds comfort in the memory of this logical conversation.

Julian is serving as a navigator in the Royal Air Force. He is aware of the grim odds of survival for flight crews but conceals this information from his fellow airmen, a group that includes a man named Blake. Instead, he boosts their morale by telling them their crew is exceptionally skilled and therefore has a better chance.

An intelligence officer summons Julian to identify a man whose face has been surgically altered for a disguise. Julian is shocked to recognize the man as his childhood friend, Guy, who is now an operative for the Special Operations Executive (SOE), the British espionage agency. Guy explains that he was captured by the Nazis and bonded with a sympathetic guard over Stendhal’s novel The Red and the Black; when a second guard identified Guy as Jewish by his nose, the first guard risked his life to help Guy escape. During the escape, a bullet struck the copy of the book he was carrying, saving his life. 

Recalling the incident, Julian remembers a childhood dare where Guy fearlessly climbed along the narrow exterior ledge of their apartment building, using a knife to carve handholds in the mortar. Julian realizes Guy’s daring and observant nature makes him perfectly suited for espionage.

A German Military Authority Ordinance dated May 29, 1942, is posted publicly in Brussels. The notice declares that wearing a Yellow Star is now mandatory for all Jews aged six and older. It also requires all Jews to register with the authorities and mandates that Jewish-owned businesses, such as hotels and restaurants, must also register and post identifying notices.

In the wake of the new ordinance, Francois Sauvin informs the architects at his firm that he will not enforce the rule requiring their Jewish members to wear yellow stars. The firm includes two Jewish men, David and Albert, and two Catholics, Jean and Christophe. David argues they must comply to feed their families, while Albert suggests they go underground. Christophe argues for compliance and states he would be more comfortable if the Jewish architects left. In response, Francois fires Christophe. David ultimately leaves without a word. A week later, the authorities shut down the firm for noncompliance with new building codes.

Francois’s neighbor, a lawyer named Martin DeBaerre, reveals he is secretly supporting a Jewish family in hiding and entrusts Francois with a sealed envelope, instructing him to deliver it to Maryanne the baker if anything should happen to him. Martin expresses frustration with his son, Dirk, who preaches riding the wave of history yet lives idly off his father. Soon after, Francois becomes tormented by a persistent phantom smell of rot and decay. He recalls telling a young Charlotte a story about a beautiful painting that outlasts the people who created it.

In November 1942, Charlotte sees her factory manager, Mr. DeDecker, confiscating loaves of bread from a woman on the street without payment. Later, in his office, DeDecker reveals he knows Charlotte’s father is unemployed and propositions her, threatening to have her conscripted for forced labor in Germany if she refuses. Charlotte lies, claiming she is pregnant with a soldier’s child; she immediately second-guesses herself for having said “officer,” worrying that Philippe’s French nationality could expose the lie. When DeDecker touches her stomach, she involuntarily vomits on him. She uses his revulsion and her threat to report him to quit her job immediately. Later, she acknowledges her pregnancy to herself and realizes that Philippe has no idea that he will soon be a father.

Charlotte’s coworker, Beatrice, tells her that DeDecker is both cheating on his wife and stealing from the VNV, the Flemish collaborationist party. To help expose him, Charlotte gives Beatrice the address of DeDecker’s lover. Later, the newsboy gives Charlotte a secret message confirming that Philippe is alive and at a parachute training school in England, likely Ringway.

Dirk DeBaerre’s father, Martin, is arrested because he was discovered to be hiding a Jewish family. To mislead his nosy neighbor Miss Hobert and avoid the shame of their association, Dirk implies his father was arrested over an affair with a man. He recalls a childhood incident where he maliciously swapped his cheap pencils for Charlotte’s high-quality set. Because Charlotte has colorblindness, she was punished by a nun for using the wrong color, which led to her being bullied by classmates.

After his father’s arrest, Dirk’s mother accidentally lets slip that Martin was not his biological father, revealing that he had already been born when she and Martin were married. Days later, when he persists in learning the true identity of his biological father, she laughs and points to her stepfather’s desk, revealing that Dirk’s real father was her own stepfather. Shortly after this revelation, she steps in front of a tram. At the hospital, a doctor informs Dirk that her injuries are fatal. Dirk instructs the doctor not to operate and sits with his mother until she dies. Afterward, he asks the doctor to officially record her death as an accident and then invites him out for coffee.

Masha is living in Paris with Harry. She poses as a Russian refugee who fled the Bolsheviks and works as a dressmaker for the wives and lovers of high-ranking Nazi-collaborating officials. This position allows her to gather intelligence, which she passes to Harry. She becomes more directly involved in his resistance work when she is asked to escort a clarinet player, Alex Vive, to the next link in an escape chain.

Harry grows increasingly tense and prone to angry outbursts. He frequently makes promises by swearing on his mother’s life and tells Masha he will send her to a safe farm in England if the situation in Paris becomes too dangerous. Masha later learns that Harry’s mother had in fact died during the previous war, 20 years before they met. Masha begins to suspect that Harry may be involved with another woman and threatens to leave for England if she discovers this to be true. Despite this, Masha reflects that her love for Harry remains unchanged.