13 Rue Thérèse, by Elena Mauli Shapiro

Odd little book. The author owns a collection of artifacts from a woman named Marie Brunet who lived in her apartment building 80 years ago. From those artifacts, she has created a story-inside-a-story of an American academic in Paris to do research who is gifted this box of artifacts by his charming and beautiful secretary. He becomes a bit mad about recreating the life of Marie Brunet, eventually becoming part of her life (i.e., going back in time). Interesting, charming--like the secretary--and offbeat.