When teenager Lea does not return home from a music festival, her parents contact the police, who uncover areas of Lea's life that her family knows nothing about.
The search for Léa gathers steam when a lead comes from a call in the night. False leads and lying witnesses plague the investigation. A confession sends Julien into a frenzy and when the police dig, this time they find something.
Police continue to interrogate their only suspect. A body is found, but is it Léa's? Flo is ready to consult a psychic to get some answers. Léa's disappearance takes its toll on Chris, and more of Léa's secrets are exposed.
Bad news is delivered and the Morel family falls into a state of upheaval as they all try to cope with their new reality. Flo's disdain with her son grows and Julien becomes obsessed with the photos taken at Léa's birthday celebration.
A suicide and a note left on an iPad sends the investigation to the next stage. Chris helps the Morels deal with their loss - especially Zoé whom Chris cares for by day. Tom provides Zoé a gift that softens his mother's anger against him.
A pendant and a pregnancy change the focus of the investigation. Romain discovers information that sends him into a rampage and shows him a secret part of Léa's life that even he did not know about. The Morels marriage starts to crumble.
The finale reveals Léa's killer, but only after taking us through twists and turns. The Morel's try to move on with their new reality, but Tom and Julien struggle to accept their new family dynamic. The final twist leaves everyone broken.
