A Very Secret Service

André Merlaux, 23, is recruited as a trainee in the French secret service. Under the supervision of operations director Moïse, three elite agents train him in the art of espionage. Responsible for African affairs, Algeria and Eastern Europe, they introduce him to a secret world dominated by the intimidating Colonel Mercaillon.

Moulinier and Jacquard succeed in capturing a former Nazi. But with Franco-German friendship now a priority, their reward is at risk. Determined to keep their bonus, they are willing to spark a diplomatic incident. Meanwhile, Merlaux meets Sophie, a young woman who quickly captures his attention.

Three emissaries from the future African state of Dahomey come to the Service demanding independence. Moulinier is tasked with bringing them to reason, but he fails. Moïse then entrusts the case to Merlaux, who eagerly takes it on, determined to prove himself in this delicate diplomatic situation.

The FLN threatens French authority in Algeria, prompting Jacquard and Merlaux to be sent on a mission. A diligent trainee, Merlaux prepares by identifying potential targets. He soon realizes Jacquard's interests in Algiers may not be purely patriotic. Focused on his duty, he confronts the enemy and experiences for the first time the harsh reality of a spy's work.

Merlaux is on a mission in Moscow with Calot. Trying to show him the ropes, Calot makes a clumsy move that triggers an incident involving the CIA. Meanwhile, Merlaux is increasingly distracted by Sophie and, driven by his feelings, prefers to go with her to see Breathless rather than focus entirely on the mission.

When Colonel Mercaillon creates a deputy director position, Moulinier, Jacquard and Calot do everything they can to secure the job. Meanwhile, Merlaux finds himself confused and unsettled by Sophie's determination to be a "modern woman" - a concept he barely understands.

The agents learn that the VG42, a surcharge inherited from the Vichy regime, is being abolished, calling into question their social benefits. Outraged, Moulinier, Jacquard and Calot go on strike. The colonel forbids Merlaux to see his daughter Sophie.

The colonel learns that Merlaux is still seeing Sophie. To dissuade him, he sets a trap with a Lebanese arms dealer. Merlaux ends up in bed with Clayborn and is filmed without his knowledge.

Moulinier, Jacquard and Calot prepare a top-secret mission to travel incognito to the United Kingdom for the France-Wales rugby match. Instead, Moïse sends them to Algiers to arrest a terrorist. Meanwhile, the colonel admits to Merlaux that he set him up during the "Monôme mission", before realising he himself is now under threat as someone within the Service investigates his past.

There is a mole in the Service! To flush him out, Moïse is lent a lie detector by Mossad. Merlaux fears that the colonel will find out from this new machine that he is still seeing Sophie. The colonel fears for his reputation: the results of the detector cast doubt on the nature of his activities during the German occupation.

The hunt for the mole stimulates Calot's paranoid tendencies. What if the culprit was none other than himself? He informs his colleagues. Meanwhile, the colonel's suspicions are confirmed: Moïse digs into his past as a collaborator. Merlaux welcomes Sophie into his home and tells her the story of an orphan raised by a priest. A priest that the colonel seems to know very well.

Colonel aims to eliminate Merlaux and sends him to Algiers to uncover a mole, a mission also assigned to Moïse. Calot struggles with identity issues while Jacquard plans an attack on General de Gaulle to protect his real estate interests. The colonel's scheme works: Moïse returns to France after eliminating Merlaux, deemed a traitor. Merlaux is buried and his file archived. Unless?