FBI cryptographer Eloise Marshall is grieving the death of her brother, who died during the attack on Pearl Harbor, when she is assigned to investigate a seemingly innocent letter about dolls. Agent Phillip Clayton is ready to enlist and head oversees when asked to work one more FBI job. A case of coded defense coordinates related to dolls should be easy, but not so when the Japanese Consulate gets involved, hearts get entangled, and Phillip goes missing. Can Eloise risk loving and losing again?

Londoner Madeleine Grant is studying at the Sorbonne in Paris when she marries charismatic French journalist Giles Martin. As they raise their son, Olivier, they hold on to a tenuous promise for the future. Until the thunder of war sets off alarms in France. Staying behind to join the resistance, Giles sends Madeleine and Olivier to the relative safety of England, where Madeleine secures a job teaching French at a secondary school. Yet nowhere is safe. After a devastating twist of fate resulting in the loss of her son, Madeleine accepts a request from the ministry to aid in the war effort.

Twenty-five years after the end of the war, Noah Ainsworth is still preoccupied with those perilous, exhilarating years as a British SOE operative in France. A head injury sustained on his final operation has caused frustrating gaps in his memory—in particular about the agent who saved his life during that mission gone wrong, whose real name he never knew, nor whether she even survived the war.

Ava thought her job as a librarian at the Library of Congress would mean a quiet, routine existence. But an unexpected offer from the US military has brought her to Lisbon with a new mission: posing as a librarian while working undercover as a spy gathering intelligence. Meanwhile, in occupied France, Elaine has begun an apprenticeship at a printing press run by members of the Resistance. It’s a job usually reserved for men, but in the war, those rules have been forgotten. Yet she knows that the Nazis are searching for the press and its printer in order to silence them.

As the Nazis march toward Paris in 1940, American ballerina Lucie Girard buys her favorite English-language bookstore to allow the Jewish owners to escape. Lucie struggles to run Green Leaf Books due to oppressive German laws and harsh conditions, but she finds a way to aid the resistance by passing secret messages between the pages of her books.

1997. Amy Novak has lost the two great loves in her life: her husband, Michael, and her first love, music. With the first anniversary of Michael's death approaching, Amy buries herself in her job as an archivist. And when a newly declassified file lands on her desk, she is astonished to uncover proof that Agent 'Colette' existed—a name spoken only in whispers; an identity so secret that it has never been verified.

July, 1940. Blitz-ridden London: Marnie Fern’s life is torn apart when her grandfather is killed in an air raid. But once she discovers that he’d been working undercover as a radio operative – or pianist – for the Dutch resistance, Marnie knows she must complete his mission – no matter the cost. Nazi-occupied Amsterdam: At the other end of the wireless, fellow pianist Corrie Bakker is caught in a dangerous game of cat-and-mouse as she desperately tries to keep her loved ones out of the line of fire – even if it means sacrificing herself.

1937. Katya Komarovsky is studying medicine in Glasgow, living among friends and eager to begin her career as a doctor. But when her spendthrift parents announce that they’ve run out of money and are facing ruin—and that she’ll now have to support them by working as a governess in Vienna—the life she’s dreamed of goes up in smoke. Furiously resentful, Katya rages at her wealthy employer, Thor, for stealing her future—and saddling her with twelve-year-old Gretchen, a deeply troubled child who has only a blazing musical talent to redeem her.

Since her husband, Josef, joined the Czech resistance three years ago, Anna Dankova has done everything possible to keep her daughter, Ema, safe. But when blonde haired, blue-eyed Ema is ripped from her mother’s arms in the local marketplace by the dreaded Brown Sisters, nurses who were dedicated to Hitler’s cause, Anna is forced to go to new extremes to take back what the Nazis have stolen from her. Going undercover as a devoted German subject eager to prove her worth to the Reich, the former actress takes on a role of a lifetime to find and save her daughter.

American Josie Anderson and Parisian Arlette LaRue are thrilled to be working in the French resistance, stealing so many Nazi secrets that they become known as the Golden Doves, renowned across France and hunted by the Gestapo. Their courage will cost them everything. When they are finally arrested and taken to the Ravensbrück concentration camp, along with their loved ones, a reclusive Nazi doctor does unspeakable things to Josie’s mother, a celebrated Jewish singer who joined her daughter in Paris when the world seemed bright. And Arlette’s son is stolen from her, never to be seen again.

As bombs fall across Europe, fourteen-year-old Lien Vinke fears that the reality of war is inescapable. Though she lives a quiet life with her mother and older sister, Elif, in their small town of Haarlem, they are no strangers to heartache, having recently suffered an immeasurable loss. And when the Nazis invade the Netherlands, joining the Dutch resistance with Elif offers just the atonement Lien craves.

Paris, 1939: Young mothers Elise and Juliette become fast friends the day they meet in the beautiful Bois de Boulogne. Though there is a shadow of war creeping across Europe, neither woman suspects that their lives are about to irrevocably change. When Elise becomes a target of the German occupation, she entrusts Juliette with the most precious thing in her life—her young daughter, playmate to Juliette’s own little girl. But nowhere is safe in war, not even a quiet little bookshop like Juliette’s Librairie des Rêves.

In 1942, Evie Farrow is used to life on Ocracoke Island, where every day is the same—until the German U-boats haunting their waters begin to wreak havoc. And when special agent Sterling Bertrand is washed ashore at Evie's inn, her life is turned upside down. While Sterling's injuries keep him inn-bound for weeks, making him even more anxious about the man he's tracking, he becomes increasingly intrigued by Evie, who seems to be hiding secrets of her own.

When Stefania Carmichael steps into the mysterious world of Bletchley Park, she immediately finds herself signing the Official Secrets Act. In whispers, she is told that she’s been recruited because of her talent for languages. Before the war ripped Europe apart, Stefania was living in Rome, charming everyone she met, and engaged to the man of her dreams, handsome and brave Matteo. And now everything has changed. With secrets swirling around the building, Stefania finds it hard to know who to trust, until she forms a close bond with two other new recruits.

In enemy-occupied Paris, as the locals go to bed starving and defeated by the war, music and laughter spills through the door of a little restaurant, crowded with German soldiers. The owner, Marianne, moves on weary feet between its packed tables, carrying plates of steaming, wholesome food for the enemy officers. Her smile is bright and sparkling, her welcome cordial. Nobody would guess the hatred she hides in her heart. That night, the restaurant closes its doors for the final time.