If this had been a western, the older gunfighter would have taught his younger rival a thing or two about the perils of a scandalous reputation before passing on the torch and (more than likely) dying tragically just as he is about to reform. Instead, in this film based on a novel celebrating the exploits of the legendary seducer Casanova, the younger competition is humbled by the fiftyish fugitive from justice because, in the art of seduction, experience is everything. In the story, Casanova (Alain Delon) is a fugitive from the wrath of the authorities of France and Italy, and he is being sheltered beneath the roof of an old friend, for whom he once did an important favor. The friend has an attractive niece, whose charms interest the almost elderly roué. However, he has two problems: his friend's wife is an old conquest who has been longing for him to show up and bed her for almost twenty years, and the niece is being courted by a handsome young soldier whose ambition is to outdo Casanova in the area of amorous adventures.