Abbé Pellegrin, parish priest of Sableuse, sells an ancient Christ to an unknown man, M. de Saint Preux. Summoned to the bishop's palace, he learns that he has been the victim of a swindler. The Christ, exchanged for a "mouthful of bread", is a valuable antique. Not wanting to compromise his wartime comrade La Goupille, who had introduced him to Saint Preux, Pellegrin proposed to his bishop that he himself carry out the search for the Christ. For the occasion, he swapped his cassock for a "civilian" outfit and landed in Paris. He recovers the treasure in the midst of a series of adventures and misadventures involving Cousinet, the former squire of Sableuse. He takes in the tenants Cousinet has just evicted from his hotel.

L'abbé Pellegrin, curé de Sableuse, un village d'environ 2100 habitants, cède à un inconnu présenté par un ancien camarade de guerre, La Goupille, un Christ ancien. Il apprend trop tard qu'il a été abusé par un escroc, Saint Preux, mais, ne voulant pas compromettre son ami La Goupille, propose à son évêque de retrouver lui-même l'escroc et le Christ.Dans ce but, il troque sa soutane contre des habits civils...