Vincent, a brilliant young man, has not taken the royal path that his studies laid out for him. Instead, he works as a baggage handler at an airport. When checking a diplomatic pouch, his colleague Gérard is killed by the explosion of a perfume bottle. Vincent surprises the bag's owner, a Syrian, picking up his luggage. The French counterintelligence agency, the DST, obliges Vincent to accept a deal: in exchange for his collaboration with the French and British secret services in catching the men implicated in the explosion, he won't be taken to court for the robberies he's committed while baggage handling. The investigation leads Vincent to London, where he must get near a British businessman, Peter Burton, who is linked to the Syrian agents. The DST and MI5 suggest that Vincent should seduce Burton's wife, Claire, a Frenchwoman with a fragile personality, so as to manipulate and get her to betray her husband. Unsettled by the challenges of the mission, Vincent soon becomes entangled in his emotions.