At a convent school for young girls, no one must know that the organist Celestin is the same person as the operetta composer Floridor. But in the long run, it cannot be hidden. His bright student Charlotte has been chosen as the bride of a man she has never met – but during a trip to Copenhagen, where Celestin is supposed to protect Charlotte from the temptations of the city, he takes her to the theatre where his operetta is to premiere. And that is where Celestin's problems really begin.