L'Ombre tells the adventures of Guillaume, a Swiss citizen, honest and cultured, a good husband and father, whose uneventful life suddenly gets out of hand. A researcher with a newspaper, he is constantly confronted with the most violent news items but only in an absent way as he isn't confronted with the danger itself. He works with Lavigne, the star journalist of the paper. Without admitting it to himself, Guillaume is jealous of his colleague who, in his eyes, is nothing but an adventurer, i.e., the one who takes all the risks, who gets all the admiration because he lives dangerously. One evening at a reception given by Lavigne, Guillaume's anguishes and fantasies erupt. His drifting starts with a painful discovery : Erika, his wife, has been unfaithful with Lavigne. Going from strange meetings to nightmarish situations, Guillaume is drawn by extreme rightists into participating to their actions and ultimately assists in Lavigne's kidnapping...