The rumblings of war in distant countries mattered little to Danny McClain. Growing up in Chicago, his world revolved around afterschool jobs, a rescued beagle, his pen pal in Holland, and the Cubs' chance to go to the World Series. Then, in December of 1941, news of the attack on Pearl Harbor hit much too close to home. In a few years, Danny found himself in the copilot seat of a B-17, stationed with the 390th Bomb Group in Framlingham, England.

It is 1941, and America teeters on the brink of war. Outgoing naval officer Ensign Jim Avery escorts British convoys across the North Atlantic in a brand-new destroyer, the USS Atwood. Back on shore, Boston Navy Yard secretary Mary Stirling does her work quietly and efficiently, happy to be out of the limelight.

When the Germans march into Denmark, Baron Henrik Ahlefeldt exchanges his nobility for anonymity, assuming a new identity so he can secretly row messages for the Danish Resistance across the waters to Sweden. American physicist Dr. Else Jensen refuses to leave Copenhagen and abandon her research-her life's dream. While printing resistance newspapers, she hears stories of the movement's legendary Havmand-the merman-and wonders if the mysterious and silent shipyard worker living in the same boardinghouse has something to hide.

When the Nazis invade Paris, Antoinette Valette’s world shatters overnight. In an instant, she goes from being a celebrated violinist, to fearing for the life of her Jewish husband and son. With nowhere to flee, hiding in plain sight is her family’s only choice.

Lt. Mellie Blake is looking forward to beginning her training as a flight nurse. She is not looking forward to writing a letter to a man she’s never met - even if it is anonymous and part of a morale-building program. Lt. Tom MacGilliver, an officer stationed in North Africa, welcomes the idea of an anonymous correspondence - he’s been trying to escape his infamous name for years. As their letters crisscross the Atlantic, Tom and Mellie develop a unique friendship despite not knowing the other’s true identity. When both are transferred to Algeria, the two are poised to meet face-to-face for the first time.

Gracie Thompson has a job, a loving family, a twin brother who drives her insane and a great friend. A chance meeting introduces her to the love of her life. But the storm clouds are gathering, Europe is teetering on the verge of war and threatening to destroy everything Gracie holds dear. When war arrives her family are split up, her younger siblings evacuated, her brothers join up to serve, her boyfriend, Charlie, is in daily danger and her life is threatened.

Never pretty enough to please her gorgeous mother, Allie will do anything to gain her approval - even marry a man she doesn't love. Lt. Walter Novak - fearless in the cockpit but hopeless with women - takes his last furlough at home in California before being shipped overseas. Walt and Allie meet at a wedding and their love of music draws them together, prompting them to begin a correspondence that will change their lives. As letters fly between Walt's muddy bomber base in England and Allie's mansion in an orange grove, their friendship binds them together.

Peter Holstein writes his popular series of adventure novels under a pen name. With European politics boiling and his own neighbors suspicious of him, Peter debates whether it might be best to change his name for good. When Rosemary shows up at his door pretending to be a historian and offering to help him trace his family history, his question might be answered. But as the two work together and Rosemary sees his gracious reaction to his neighbors' scornful attacks, she wonders if her assignment is going down the wrong path.

London, 1941. The Blitz. When a Royal Navy memo arrives at head office, requesting female recruits to sign up as motorcycle dispatch riders, delivering highly classified orders across the country, three women jump at the chance to sign up for the most dangerous jobs in London.

In 1944, American naval officer Lt. Wyatt Paxton arrives in London to prepare for the Allied invasion of France. He works closely with Dorothy Fairfax, a "Wren" in the Women's Royal Naval Service. Dorothy pieces together reconnaissance photographs with thousands of holiday snapshots of France - including those of her own family's summer home - in order to create accurate maps of Normandy. Maps that Wyatt will turn into naval bombardment plans. As the two spend concentrated time together in the pressure cooker of war, their deepening friendship threatens to turn to love.

Somewhere in the Pacific, 1943. Kate Campbell is a nurse who bravely flies back and forth from the front to rescue wounded soldiers, amid long days, harsh conditions and often dangerous weather. Driven by a deep personal need to help in the war effort, she is conflicted when an injury results in her reassignment to the relative comfort of the English countryside. Love has never been part of her plan, but despite herself, she falls for an officer with three bullet wounds, startling blue eyes and a wicked sense of humor.

Amsterdam, 1941. German forces have invaded Amsterdam. As the tension in the city increases, the Dutch Resistance is born. Tormented by what is happening in his city, Christiaan joins the Resistance. He risks everything to shield the oppressed and fight for the freedom of his beloved nation. His brother—Floris—is ruthless and driven to succeed. Promoted to the Bureau of Jewish Affairs, he becomes instrumental in hunting Jews to transport them to the Nazi death camps.

Liverpool, 1935: Raised in a strict Catholic family, Viv Byrne knows what’s expected of her: marry a Catholic man from her working-class neighborhood and have his children. However, when she finds herself pregnant after a fling with Joshua Levinson, a Jewish man with dreams of becoming a famous jazz musician, Viv knows that a swift wedding is the only answer. Her only solace is that marrying Joshua will mean escaping her strict mother’s scrutiny. But when Joshua makes a life-changing choice on their wedding day, Viv is forced once again into the arms of her disapproving family.

Robinswood, Co. Waterford, 1939. The once grand house is home to two very different families. Despite delusions of grandeur, Lord and Lady Kenefick and their adult children live a life of decayed opulence as the money needed to keep such a large house and grounds ever dwindles. Meanwhile, the Murphy family, Dermot, Isabella and their three almost grown-up girls, live and work on the estate and do their best to keep everything running smoothly.

When her husband doesn’t come home one day, Ariella realises that the only way she can ensure her Jewish children’s safety is to avail of the Kindertransport, but can she bear to let them go? A thousand miles away, Elizabeth Klein has closed herself off from the world. Losing her husband on the last day of the Great War, and her child months later, she cannot, will not, love again. It hurts too much. But she is all Liesl and Erich Bannon have.