Dieter Vogel, a German industrialist, believes in protecting his family at all costs, but in a bid to keep his English wife and children safe, he is plunged into a well of deceit that tears the family apart. Doctor Paul Vogel is coerced into working in the Nazi eugenics program and soon discovers that sterilizing handicapped and mentally-ill Germans is just a prelude to a more lethal plan against those the Reich deem unworthy of life. Paul, trapped by the SS, seeks help from the unlikeliest of people and is plunged into a world of espionage and murder.

January 1944—a senior member of the French Resistance betrays his comrades to the Abwehr and Gestapo, but who? Within hours, the Germans arrest hundreds of suspected resistance fighters and incarcerate them in the infamous Amiens prison. When a Resistance spy inside the prison informs his leaders, Dominique Ponchardier and Boniface Monier, of German plans to conduct mass executions within weeks, they are helpless to respond. In a last-ditch effort to free their Résistants awaiting death or deportation to labor camps, they turn to the British for help.

It is 997 CE, the end of the Dark Ages. England is facing attacks from the Welsh in the west and the Vikings in the east. Those in power bend justice according to their will, regardless of ordinary people and often in conflict with the king. Without a clear rule of law, chaos reigns. In these turbulent times, three characters find their lives intertwined.

1940. In a world newly burning with war, and in spite of her American family’s wishes, Virginia d’Albert-Lake decides to stay in occupied France with her French husband. She’s sure that if they keep their heads down, they’ll survive. But is surviving enough? Nineteen-year-old Violette Szabo has seen the Nazis’ evil up close and is desperate to fight them. But when she meets the man who’ll change her life only for tragedy to strike, Violette’s adrift.

Occupied Poland, 1942: Despite the constant presence of German soldiers in her village, Emilia is allowed certain freedoms as a midwife—the most precious is innocently cycling past Nazi checkpoints to the homes of expectant mothers on her rounds. But Emilia has a secret: for years she’s also been visiting the hidden Jewish mothers and working for the resistance…until she is betrayed.

London, 1940. Bombs fall and Josie Banks’ world crumbles around her. Her overbearing husband, Stan, is unreachable, called to service. Her home, a ruin of rubble and ash. Josie’s beloved tearoom boss has been killed, and Josie herself is injured, with nothing left and nowhere to go. Evacuated to the English countryside, Josie ends up at the estate of the aristocratic Miss Harcourt, a reluctant host to the survivors of the Blitz. Now a threat looms larger than anyone imagined. And a dangerous secret is about to upend Josie’s life again.

Berlin, 1930—When a wave of change sweeps a radical political party to power, Sofie von Meyer Rhodes’s academic husband benefits from the ambitions of its newly elected chancellor. Although Sofie and Jürgen do not share the social views growing popular in Hitler’s Germany, Jürgen’s position with its burgeoning rocket program changes their diminishing fortunes for the better. But as Sofie watches helplessly, her beloved Berlin begins to transform, forcing her to consider what they must sacrifice morally for their young family’s security, and what the price for their neutrality will be.

In the snowbound city of Kiev, wry and bookish history student Mila Pavlichenko organizes her life around her library job and her young son—but Hitler’s invasion of Russia sends her on a different path. Given a rifle and sent to join the fight, Mila must forge herself from studious girl to deadly sniper—a lethal hunter of Nazis known as Lady Death. When news of her three hundredth kill makes her a national heroine, Mila finds herself torn from the bloody battlefields of the eastern front and sent to America on a goodwill tour.

1942. Hannah Martel has narrowly escaped Nazi Germany after her fiancé was killed in a pogrom. When her ship bound for America is turned away at port, she has nowhere to go but to her cousin Lily, who lives with her family in Brussels. Fearful for her life, Hannah is desperate to get out of occupied Europe. But with no safe way to leave, she must return to the dangerous underground work she thought she had left behind.

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.

1944. Physics professor Alfred Mendel and his family were trying to flee Paris when they were caught and forced onto a train, along with thousands of other Jewish families. At the other end of the long, torturous train ride, Alfred is separated from his family and sent to the men’s camp, where all of his belongings are tossed on a roaring fire. His books, his papers, his life’s work. The Nazis have no idea what they have just destroyed. And without that physical record, Alfred is one of only two people in the world with his particular knowledge. Knowledge that could start a war, or end it.

Fourteen-year-old Rivka Resnik survives the brutal massacre of her family in Lithuania, only to spend the rest of the war fighting as a partisan against Nazi forces, then surviving as a prisoner in Auschwitz. Finally rescued and sent to America, Rivka soon faces the SS officer who commanded the death squads that murdered her family. Now, it is Rivka’s turn to become the hunter.

Occupied France, 1940. When the staff at a field hospital draw straws to find out who will join the evacuation from Dunkirk, Nurse Cate is left behind. But when the Nazis arrive to claim prisoners of war, she takes her chance and flees into the night, taking one patient with her. Fifty miles away, the surrendering soldiers of the Royal Norfolk Regiment are shot dead by the advancing Germans. Beneath the pile of bodies two men survive, crawling to the safety of a nearby farmhouse, where sisters Elise and Adelaide risk their lives to take them in.

Between the World Wars, the six Mitford sisters—each more beautiful, brilliant, and eccentric than the next—dominate the English political, literary, and social scenes. Though they've weathered scandals before, the family falls into disarray when Diana divorces her wealthy husband to marry a fascist leader and Unity follows her sister's lead all the way to Munich, inciting rumors that she's become Hitler's mistress.

At the height of WWII, five idealistic young Americans receive a mysterious letter from the OSS, asking them if they are willing to fight for their country. The men and women from very different backgrounds - a Texan athlete with German roots, an upper-crust son of a French mother and a wealthy businessman, a dirt-poor Midwestern fly fisherman, an orphaned fashion designer, and a ravishingly beautiful female fencer - all answer the call of duty, but each for a secret reason of his or her own. They bond immediately, in a group code-named Dragonfly.