Landes, 1999: 11-year-old Charlotte Meyer vanishes without a trace. The prime suspect is released by the Police Captain for lack of evidence. Twenty years later, a young detective finds herself faced with a similar case.

Sarah tries to tie Charlotte's disappearance to the Fanny Vidal case, convinced Fouquet is responsible for the disappearance of the new victim as well. But as Sarah interrogates the suspect, he tricks her into making an error.

Sarah manages to link the two girls' disappearances and piles up evidence against Fouquet. She is troubled when her old high-school boyfriend slips back into her life, oblivious to the fact he's a suspect in Meyer's case.

Fouquet has all the trappings of a dangerous child predator. Sarah is sure she's found the man behind Meyer's and Vidal's disappearances. She starts seeing Tony again, unaware that he's been incriminated in her own investigation.

The DNA found on Meyer's boots leads to a surprising female suspect. Realizing the woman is also involved in Vidal's disappearance, Sarah races to find the little girl before she suffers the same fate as Charlotte, in the finale.