Charlotte, NC. 1918. Broadway darling Calla Connolly had it all: a rising career on the stage and a loving fiancé, a fellow stage actor. But after his tragic death early in the war, Calla is touring the American training camps, hoping to convince General Pershing to let her tour the French front to cheer the men and honor her fiancé's memory. But her hopes are dashed when she contracts Spanish flu while performing at Camp Greene.

Colette Marceau has been stealing jewels for nearly as long as she can remember, following the centuries-old code of honor instilled in her by her mother, Annabel: take only from the cruel and unkind, and give to those in need. Never was their family tradition more important than seven decades earlier, during the Second World War, when Annabel and Colette worked side by side in Paris to fund the French Resistance. But one night in 1942, it all went wrong.

2016: Thirty-four-year-old Mari Starwood is still grieving after her mother’s death as she travels to the storied island of Martha’s Vineyard, off the coast of Massachusetts. She’s come all the way from California with nothing but a name on a piece of paper: Elizabeth Devereaux, the famous but reclusive Vineyard painter. When Mari makes it to Mrs. Devereaux’s stunning waterfront farm under the guise of taking a painting class with her, Mrs. Devereaux begins to tell her the story of the Smith sisters, who once lived there.

Morocco, 1928. Marie-Madeleine Méric is not the kind of woman who stays quietly at her husband’s side. Polyglot, pianist, and pilot, she is a woman of many skills, with unconventional interests—like driving in car rallies—that earn her a daredevil reputation. But dabbling in intelligence work to assist her military officer husband and the French government helps her recognize who she is at heart: an adventurer.

1940, Italy. Lili and Esti have been best friends since they first met at university. When Esti’s son Theo is born, they become as close as sisters. While a war seethes across borders, life somehow goes on—until Germany invades Italy, and the friends suddenly find themselves in occupied territory. Esti, older and fiercely self-assured, convinces Lili to join the resistance efforts. But when disaster strikes, a critically wounded Esti asks Lili to take a much bigger step: To go on the run with Theo. Protect him while Esti can’t.