The Librarians of Rue de Picardie

Under what was left of the roof of the ruined cottage, a girl with pigtails perched on a pile of rubble, hunched over a book...
1918: As the Great War rages, Jessie Carson leaves the New York Public Library for the American Committee for Devastated France. Joining the women rebuilding French communities, Jessie strives to establish something new - children's libraries. She turns ambulances into bookmobiles and trains the first French female librarians. Then she disappears.
1987: Librarian Wendy Peterson stumbles across a reference to Jessie Carson in the archives. Consumed by her story, Wendy learns that she and the elusive librarian have more in common than the NYPL. Wendy's obsession leads to their paths converging in surprising ways across time.