Marcello Mastroianni espies a young woman who is waiting, patiently, by a bridge. Initially he thinks she is one of the ladies of the night but as he passes he thinks he hears her crying. Distressed, she tries to flee from him but he manages to calm her down and they chat. They agree to meet next evening, same place same time - and that's the start of this charmingly simple drama that sees "Mario" and "Natalia" (Maria Schell) begin to confide in each other and cement a bond borne out of both of their emotional desires and frustrations. We also find out just why she waits each night. There…