Noël Schoudler is the autocratic head of diversified family enterprises which include a bank, a newspaper and a sugar refinery. His only son François considers the whole set-up archaic and, while his father is on a business trip to the USA, starts jazzing up the staid newspaper. On his return, the father is furious and decides to teach his son a lesson. He tells François that he can have the run-down sugar business, to manage as he pleases. Painfully lacking the necessary expertise, the young man launches into enthusiastic modernisation and expansion. It is rapidly brought home to him that he needs capital, which he will have to raise.