As the investigation continues and terrorists plan a further attack in France, a man comes forward with links to Robert. Elise uncovers disturbing facts about Eryka's past and Karl follows a hunch.

Karl and Elise receive a tip-off from a woman they believe knows Robert Fournier's whereabouts. But can she be trusted?

As a young mother-to-be helps Karl and Elise with their enquiries a new development threatens to tear the pair's partnership apart.

Karl makes a foreboding discovery at Elise’s apartment, and the pattern of missing people continues.

In the final episode, Karl and Elise face a tense and gripping showdown with the Pied Piper, while the truth about the Moreau abduction is revealed at last.