In 1977, a passenger plane crashes. The sole survivor is a three-month-old baby. But there were two little girls of the same age on board, Emilie Vitral and Lyse-Rose Carville. The grandparents of the two babies fight to gain custody of the miracle child and Chief Inspector Monod heads up the enquiry. Justice renders its verdict: "Lili" is entrusted to the Vitrals, as they did not find t..

In 1978, hired by the Carvilles after the legal proceedings, Monod discovers that the bracelet in fact was stolen by Pelletier, a hippie who was present the night of the crash. With the aid of her flatmate Nina, Lili escapes police surveillance and goes to Mathilde Carville's to suggest that they both do a DNA test (which didn't exist in 1978 but is now fine-honed). Bouazi and Martineau, the cops..

Saved in extremis by Bouazi, Lili feels hopeless. If she is effectively Marc's sister, she must put a term to her pregnancy. Finally understanding how crazy and dangerous Hortense is (Hortense is Bouazi's mistress), and knowing she is still persuaded that Lili is her sister, Bouazi releases Marc whom he was holding prisoner and asks for backup. But Hortense kills Bouazi. We find Monod in the Vosg..

If Lili is neither Lyse-Rose nor Emilie, who is she? Jacques continues his enquiry at an inn owned by a certain Jeanne Longval and warns her that Hortense will carry on killing anyone who discredits her outrageous theory. Marc and Lili find Monod, seriously wounded. He begs Lili: she must find a newspaper. At the home of the firefighter who saved her as a baby, twenty years before, Marc and Lili d..