The Paris daughter / Kristin Harmel.

"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, and, when a bomb falls on their neighborhood, Juliette's world is destroyed along with it. More than a year later, with the war finally ending, Elise returns to reunite with her daughter, only to find her friend's bookstore reduced to rubble--and Juliette nowhere to be found. What happened to her daughter in those last, terrible moments? Juliette has seemingly vanished without a trace, taking all the answers with her. Elise's desperate search leads her to New York--and to Juliette--one final, fateful time." - Publisher