In this surreal comedy, Tonio works very hard for every bit of ill-gotten cash he can get his hands on, but he remains a poor criminal in both senses of the word. He and his buddies Bruno and Hercule think they have the solution to their pocketbook woes. The body of St. Bernadette has been miraculously preserved from decay and is a central object of pilgrimage in the shrine where it is kept. Why not steal that and hold it for ransom? The criminal gang is well able to pull this coup off and are soon in possession of one perfectly preserved corpse and a very fancy coffin. It's too bad for them that the church seems to have a limitless supply of these and doesn't want the one they stole back. Bemused, the lads set the coffin adrift on the river, only to be followed by it as they drive back upriver. In the course of carrying out their criminal designs, these lovable lugs encounter a variety of eccentric characters.

Trois arcandiers, c'est-a-dire dans le patois du centre de la France des êtres fantaisistes et brouillons, décident de partir au Brésil tandis que, quelques kilomètres plus loin, a Nevers, Bernadette Soubirous s'ennuie dans sa chasse. Elle va les accompagner a leur insu et les entrainera jusqu'au bout de leur rêve.