Edouard and Félix, two delivery men for a Paris department store, are so passionate about theirs jobs that not only do they take their work to heart but they also consider themselves as responsible for their customers' happiness. Which leads them to help in turn, at the cost of incredible acrobatics, two young people who are celebrating their first wedding anniversary, to mix with the patients of a rather strange doctor, to almost die in an ambush not intended for them and at last to avoid a quarrel between a husband and his wife.