Pierre Brochant (Thierry Lhermitte) is a successful publisher. Every Wednesday Pierre and his cronies have an 'idiot's dinner', when they invite an idiot to share their meal. Whoever invites the biggest idiot wins. Pierre is convinced he has found the biggest idiot ever - an accountant called François Pignon (Jacques Villeret). However, no sooner has this prize idiot been invited, than Pierre's life starts to fall apart. It seems that François is a jinx of mammoth proportions.