A decade after tragedy upended his family's life, Guillaume is ready to embark on a new chapter - until his girlfriend suddenly disappears.

Guillaume digs into his mother's mysterious spending and uncovers a clue to Judith's past. In 2010, Sonia's sister hides a key piece of evidence.

Judith's mother visits Guillaume with more startling news. A trip to Ivry forces Daco to reckon with a secret from his own past.

Desperate for answers, Guillaume confronts Fred's closest confidant. In Italy in 2015, a budding friendship leads to a life-changing encounter.

As flashbacks reveal young Fred's transformation, Guillaume finally learns the truth about his brother - and that fateful night 10 years ago.