An inexperienced, sickly priest shows up in the rural French community of Ambricourt, where he joins the community's clergy. But the locals don't take kindly to the priest, and his ascetic ways and unsociable demeanor make him an outcast. During Bible studies at the nearby girls school, he is continually mocked by his students. Then his attempt to intervene in a family feud backfires into a scandal. His failures, compounded with his declining health, begin to erode his faith.

Thérèse, a young flower girl, tries hard to remain virtuous but the whole world seems to conspire against her, whether her petty Paris family, or her relatives in the province bristling with false respectability, or her lustful employer, or the boy she loves who seduces her and abandons her. But at the end of the day there is Yvon, her childhood friend. Will he be the one that will love her truly?

An early example of ultra-realism, this movie contrasts the quiet, bucolic life in the outskirts of Paris with the harsh, gory conditions inside the nearby slaughterhouses. Describes the fate of the animals and that of the workers in graphic detail.