Tragedy strikes when five-year-old Oliver goes missing on a family holiday to France.

Progress into the case is initially slow but a shocking new lead emerges.

The stress of the reopening of the case takes a toll on Emily and Mark's relationship.

In the present day, Tony and Julien make a breakthrough.

Tony and Emily return to Chalons du Bois and their relationship thaws.

The truth about Oliver's disappearance finally comes to light.