Professor Louis Delage is a kidney transplant specialist. He is so good in his field that his peers nickname him the "great man". But one day, one of his patients die during surgery and Delage starts doubting. Is he actually such a great man? To fight desperation he decides to take in the deceased child while devoting more time to Florence, his hitherto neglected wife.

Naturally optimistic and mischievous, Jérôme Aubin crossed the time of his adolescence, around 1945, with ease and good humor. The years passed. He married the pretty Françoise, a little neighbor he had known since the age of eight, and soon found himself a secondary school teacher, a little anxious at the thought of facing for the first time students he had been told were particularly turbulent. How will he master this new difficulty? Better than you'd think, thanks to a delicious optimism: boldly going against the grain of conventional methods, he surprises his young audience, thwarting the plans of the dissipated gossips and turning their most tendentious attitudes to his advantage. All this provokes astonishment and concern among the college's leaders. But Jérôme Aubin is no pushover, and even the dreaded general supervisor finds himself obliged to give in to his most audacious initiatives...