Paris in the spring of 1867: A few days before the official inauguration of the World Fair, the dead body of a child is found in the river Seine. The mother is arrested and accused of infanticide. She denies having killed her child and claims to have left it at a hospital for treatment a few days before. But nobody in the hospital remembers anything …

Paris in the spring of 1992: What mystery surrounds a young French woman in a library in Paris who obsessively researches this long forgotten case of infanticide? Bruno, a 27-year-old architect who is looking for material for his thesis on the 1867 World Fair, needs some of the books the young woman is reading. Reluctantly, she agrees to share some of the material with him. Bruno soon falls in the love with her, but she refuses his advances. Until he starts taking an interest in the strange case she is determined to uncover.