A Haitian woman arrives at the office of Leduc Detective proclaiming that she is Aimée Leduc's sister, her father's illegitimate daughter. Aimée is thrilled; she has always wanted a sister. Her partner, René, is wary of this stranger, but Aimée embraces her. She soon unearths a secret that leads her to a murder in the old university district of Paris, the Latin Quarter.