The Riviera House

In Paris in 1939, twenty-year-old Éliane Dufort attends art history lectures at the École du Louvre and works at the museum to support her struggling family. Her parents pour every franc into a failing brasserie, leaving Éliane to raise her four younger sisters. Her older brother Luc reintroduces her to Xavier Laurent, a young painter whose father owns galleries in Paris, London, and New York, and a romance develops. As war looms, Monsieur Jaujard, the Director of France's national museums administration, orders the Louvre evacuated. Éliane helps pack artworks into coded crates and memorizes the Mona Lisa's secret code. During the removal of the Winged Victory of Samothrace, she and Xavier hold hands for the first time.

After Germany invades Poland and France declares war, Xavier proposes with a star sapphire ring following their first night together, then reveals he must leave for England because his father is closing the Paris gallery. Feeling betrayed, Éliane throws the ring at him. She sends her mother and sisters south to escape the German advance, but months pass without word. Luc concludes they were likely killed when Luftwaffe planes strafed columns of refugees. The Germans occupy Paris, and Luc departs to join de Gaulle's Free French Forces, leaving Éliane alone with a vow to make the Nazis pay.

Jaujard sends Éliane to the Jeu de Paume museum to assist Rose Valland, the reserved former curator, where the Einsatzstab Reichsleiter Rosenberg (ERR), a Nazi taskforce for seizing art in occupied territories, stockpiles works confiscated from Jewish families. Colonel von Behr heads the operation, while his nephew Ernst König, a German art historian, allows Éliane to catalog paintings. When Hermann Göring, one of the most powerful Nazi leaders, visits for a private exhibition, Éliane is stunned to see Xavier at his side, acting as his art adviser. Xavier keeps secret her knowledge of German, which Jaujard instructed her to hide, but warns her that discovery means death. Éliane and Rose slip into von Behr's office and find Göring's signed orders: The Jeu de Paume is a transit point for systematic plunder, with first choice of stolen art going to Hitler and second to Göring.

Éliane's fifteen-year-old sister Angélique returns alive from the south with devastating news: Their mother and three youngest sisters were killed during the exodus. When Angélique accuses Éliane of working for the Nazis, Éliane resolves to document every theft. She joins Rose, Jaujard, and Luc in a clandestine resistance effort, understanding there is no going back.

The novel shifts to 2015. Remy Lang, a vintage fashion seller, arrives at an inherited house in Saint-Jean-Cap-Ferrat on the French Riviera, grieving the deaths of her husband Toby and daughter Emily in a car accident. She befriends her neighbors, including fashion photographer Adam Henry-Jones, his sister Lauren, his brother Matt, and Matt's five-year-old daughter, Molly. Remy learns Adam is Molly's biological father but was shut out of her life. Her best friend and former colleague Antoinette arrives from New York to help when Adam photographs Remy's lookbook. As they share confidences about their losses, a bond forms. They discover Le Catalogue Goering, a record of Göring's stolen art. Remy recognizes a painting from her bedroom wall listed as Le Traître (The Traitor), a work that has accompanied her since she was adopted as a baby.

In the wartime narrative, Éliane and Rose begin their espionage. Éliane exploits König's infatuation for access to his records and discovers Göring's master catalogue along with a code book matching shipment codes to Nazi depots in Bavaria, which Rose copies. Reasoning that overhearing Nazi conversations will yield intelligence, Éliane offers the brasserie as a restaurant for German officers. Rose and Éliane swap a Fragonard painting meant for Hitler into Göring's crates to fuel rivalry between the two leaders, but when the switch is discovered, von Behr fires Rose. A mysterious travel permit appears in König's bouquet; Éliane uses it to send Angélique to a Louvre depot in the south.

Xavier then reveals his true role: He is not a collaborator but a British agent inserted into Göring's circle because of his art connections, protecting Éliane and feeding intelligence to the Allies. The revelation shatters Éliane, who has spent years hating him. At a weekend party on the Riviera, she drugs König's drink to avoid sleeping with him and passes Xavier intelligence about the Schloss collection, a valuable Jewish art collection hidden nearby.

In 2015, Remy and Adam investigate the painting's origins. At the Louvre, Lauren's friend Chloe shows them a companion work signed by Luc Dufort. In Washington, researcher Taylor Edwards, whose grandmother bought Xavier Laurent's gallery, argues Xavier painted both works and reveals that König's diary describes him having a child with Éliane in 1944. Remy's birth father was Alexandre König, a scientist from East Germany who was shot escaping over the Berlin Wall; his pregnant partner made it to England but died giving birth to Remy. Remy realizes Alexandre may be the child described in the diary, making her potentially the granddaughter of a Nazi. She and Adam visit Elke König, Ernst's wife, in Paris, where Elke reveals Ernst poisoned himself at war's end.

As the wartime story reaches its climax, Éliane and Xavier spend one secret night together. Éliane discovers she is pregnant with Xavier's child but tells König the baby is his to protect the group, naming the boy Alexandre. Xavier gives her the deed to his Cap-Ferrat house and proof he bought both paintings from Rothschild. König, delighted by what he believes is his son, demands Éliane leave Alexandre with Elke during the day. Meanwhile, Éliane discovers Xavier's signature hidden beneath white paint on one of the paintings, confirming Luc stole Xavier's work. She also uncovers that Luc has been selling information to the SD, the Nazi intelligence service, in exchange for money and status with the Maquis, rural Resistance fighters.

In 2015, Remy and Adam fall in love. When Elke returns to Cap-Ferrat, she reveals Ernst was likely not Alexandre's biological father and produces a letter from Angélique explaining a contingency plan to rescue the baby from a train evacuating art from Paris. Remy decodes initials on the paintings using the same coding system from the Louvre's wartime evacuation: XL/ED for Xavier Laurent and Éliane Dufort, AD for Alexandre Dufort, their son. Taylor discovers in Nazi records that Luc betrayed Xavier and Angélique to the SD, which also led the Nazis to Éliane. The entry Le Traître in Göring's Catalogue records not the painting's true title but Luc's treachery. Both Xavier and Éliane were killed at Buchenwald concentration camp.

Remy discovers she is pregnant and, terrified of losing another child, flees to New York without telling Adam. She communicates only through Antoinette and refuses to bond with the baby. After giving birth to a son, she hemorrhages severely and nearly dies. Adam, who flew to New York when Antoinette called about the labor, has been at the hospital for five days. Remy wakes, tells Adam she loves him, and names their son Xavier after her grandfather.

In the final wartime sequence, König demands Alexandre in exchange for Luc's freedom. At the station, Luc reveals he betrayed Angélique to the SD. He leaps onto the departing train, seizes the painting, and holds it as a shield over Alexandre before being shot dead. Guards drag Éliane away. The epilogue reveals that König and von Behr poison themselves at war's end, Rose Valland spends decades recovering stolen art, and Angélique dies at Fresnes prison without revealing names. At Buchenwald, Éliane finds Xavier; they embrace and become the couple from the painting, together at the end. The painting passes through generations, above Remy and Adam's bed, then above their son Xavier's, onward through time.