The group is in Geneva, where Lisa's backpack was recovered. Zoë receives an anonymous note from someone claiming to know Lisa. In the Alps, disaster strikes when Piet loses his balance and Asim plunges to death trying to save him.
Lisa's cell phone case turns up near a burned-out hut. There, investigators discover Lisa's fingerprints dating from two years after her disappearance. Inspector Pol Martin seems to know more than he is willing to share.
The traumatic events seem to have put an end to the commemoration. Piet meets inspector Pol Martin where he last spoke to his daughter. Asim turns out to be the driver of the red van that Lisa got into just before her disappearance.
Asim's arrival divides the group. They learn that during her stay in the Ardennes, Lisa found out that her father had an affair. Asim confesses that he is on the run. In Luxembourg, the group discovers a new trace of Lisa.
The journey continues through the desolate region of la Lorraine. Bart, Ylena's husband, visits the group with his camper. Piet discovers that Lisa and Bart have seen each other during her journey. Asim's past finally catches up with him.
After the devastating events in the Alps, the group falls apart and Zoë continues the GR5 hike on her own. Upon her arrival in Nice, she finally discovers what really happened to Lisa.
The group sets out with Piet trailing behind. It becomes clear that they all have different reasons for making the journey. Asim, Lisa's ex-boyfriend and former jihadi, wants to join the hike.
Five years after Lisa went missing on the hiking trail GR5, her friends Zoë, Michiel, and Ylena decide to make the same journey to commemorate her. They are unexpectedly joined by Piet, her father.