Pioneers struggle to establish a town in the harsh unsettled wilderness of northern Quebec during the depression.

Filmed in French, this Canadian film was based on a popular Quebec-based radio serial. The man of the title is miserable miser Seraphim (Hector Charland). Misanthropic to the point of insanity, Seraphim takes great pleasure in destroying the lives of everyone with whom he comes in contact. His current target is Alexis (Guy Provost), the ex-lover of Seraphim's long-suffering wife Donalda (Nicole Germain). Taking into consideration its daytime-drama source, it's understandable that Un Homme et Son Peche is plotted and paced like a soap opera. Star Hector Charland had previously spent 10 years portraying Seraphim on radio, so he's got plenty of "mean" at his disposal for this big-screen spin-off.

A dramatized story about a town where illegal activities are allowed to thrive, some of the politicians are dishonest, and a doctor and couple of colleagues try to help townspeople see that public health measures, especially those that might control syphilis, are necessary. Two of the most influential men in town oppose clean-up and public health efforts until their young adult children contract syphilis. Spliced into the dramatic film are segments of other educational films, including animated segments, that describe the symptoms and risks of syphilis. A butcher named Tony is excited about the birth of his first child, but the child is born dead because of a maternal syphilis infection.

A health problem causes a business leader to think about what will happen to his company after his death.