Debailly is prisoner of IS in Iraq. DGSE asks Nadia to negotiate his release through an intermediary Shahanah, a corrupt art dealer, and promises her an EU Deputy Commissioner position in return for her help. Sisteron is sent to Iraq to meet Kurdish fighters and rescue him, but their attempt to do so during a sandstorm fails

One of Debailly's jailers is a Russian FSB mole and offers to help him. Meanwhile, Duflot tries to help Marina overcome her trauma. Shahanah takes Nadia to meet Lely, a female intermediary for IS

Debailly loses hope after his FSB helper is wounded, and stops eating. Marina is approached by Phillipe, a Mossad agent who is posing as DGSE and wanting to recruit her. DGSE advises her to accept the offer, and report everything back to them

The CIA wants to bomb the camp where Debailly might be held, but DGSE insists they wait. Duflot wants to get Debailly released before he retires, but MAG reminds him that the agency doesn't normally make much effort to rescue disloyal agents. DGSE use Prune to pressure Nadia into agreeing to resume negotiations; Nadia meets Lely again and is given the hostage video

Shahanah is murdered by the Iranians. DGSE sets up a secret meeting between Duflot and Cochise near Jarabulus, and Duflot prepares for his mission. Lely asks to meet Nadia again, and DGSE suspects IS may have lost Debailly; their agents in Iraq confirm he has escaped

Debailly manages to escape into the hills, and seeks help from a farmer who betrays him to IS, and he is recaptured. French agents identify the area where he escaped, but arrive too late. In Baku Marina gives her presentation to the conference, and is offered a job there, which Mossad urges her to take; she agrees after consulting DGSE

Cochise refuses to spy for DGSE within IS, wanting exfiltration. Duflot agrees, if Cochise can free Debailly. Before he can return, Duflot is shot by one of Cochise's men; he is taken to hospital but later dies

DGSE mourns the loss of Duflot. Meanwhile, Mossad gives Marina the memory stick with the virus, which DGSE manages to copy before Marina successfully introduces it into the system. In Iraq, Cochise and his IS fighters take Debailly toward an arranged ambush with French special forces

DGSE discovers that Debailly is using the stolen IDs of former agents to travel back to France. Nadia hears from her assistant's Iranian contact that Debailly is free, but DGSE refuses to tell her anything; they use Prune to tempt Debailly into making contact with her. Debailly uses burner phones to contact Prune, and then gets a message to Nadia

DGSE tracks Debailly's attempts to contact Nadia. Dr Balmes meets her, and explains how Debailly got her released from captivity. Debailly sets up a plan to meet Nadia in a hotel, contacting her via her assistant's mobile, which DGSE is already monitoring for another operation