1918: As the Great War rages, Jessie Carson takes a leave of absence from the New York Public Library to work for the American Committee for Devastated France, a group of women determined to rebuild devastated French communities just miles from the front. Upon arrival, Jessie strives to establish something that the French have never seen – children’s libraries. She turns ambulances into bookmobiles and trains the first French female librarians. Then she disappears. 1987: When NYPL librarian and aspiring writer Wendy Peterson stumbles across a passing reference to Jessie Carson in the archives, she becomes consumed with learning her fate.