The story of Itineraire Bis has no singular plot line, but swings back and forth between the adventures of a young man who wants to buy a pizza truck and the lives of two middle-aged brothers living in an enormous house. One of the brothers is wheelchair-bound and eventually makes the acquaintance of the pizza-driving aspirant and decides to give him the money he needs -- though this act of generosity in no way shields him from his own destiny. Other characters wander in and out of the story, such as Jeanne (Martine Kalayan), the young man's lover.

Robert projette de s'acheter un camion pour être marchand ambulant avec Jeanne son amie. Mais il lui faut trouver l'argent et se rend pour cela chez un ancien ami Charles. Celui-ci devenu infirme ne peut l'aider, il vole donc à son frère ses économies et achète le camion pour Robert...