A mature, rich and bored woman called Elisabeth is taking a ride with the “Rheingold”, a first-class high-speed train of the seventies along the river Rhine. In the train she is meeting her old school mate and lover who is working as a waiter and falls in love with him again. Her husband, a busy politician, realizes what’s going on and tries to catch the train to face his wife and her lover in a fatal showdown.

Rudi, who’s been quite the ladies’ man, finally wants to settle down and marry Hilde. So as to not get into a touchy situation with all his many women, he plans to bring them all together the night before his wedding. While sitting alone in his apartment and burning all his old photos and love letters, he notices a woman in the garden. She assets, that she’s hiding from a stubborn admirer and he stupidly offers her to come in … and then it all begins! First, his wife-to-be Hilde shows up, who wants to spend the night before their wedding together. While Rudi tries to hide the unknown woman in his bedroom, a hotel detective shows up and claims he’s following a thief.