Tragedy strikes when five-year-old Oliver goes missing on a family holiday to France.
Tony's investigation gathers momentum as he finds the first bit of concrete evidence.
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 2006, Tony and Emily's pleas to reinvestigate a suspect again fall on deaf ears.
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.