François Sim considers himself worthless and he may have good reasons for that. Hasn't he lost his job as well as his wife Caroline? Isn't he unable to relate to Lucy, his teenage daughter? Didn't he, when he was eighteen miss out on passion whereas the sexy, gorgeous Luigia opened her arms to him? Hasn't he - he who keeps craving communication - invariably proved a dreadful bore to others...? So, when Sim is unexpectedly offered a job, he takes it, hoping one more time to give a little bit of meaning to his life. Even if his task amounts to driving across France and trying to sell... a "revolutionary biological toothbrush" to reluctant dentists!