Three women living together, supporting themselves through prostitution, want to change their situation. They save the money they make from their clients, so they can move on to a decent living, once they've made enough money. We're shown in flashbacks how these women met and episodes from their dust-ins with various clients.
"Mädchen I'm Nachtverkehr" is mainly for the initiated, but I would definitely recommend Francophiles-in-the-making to give this one a spin as it will only increase your appreciation for him, and his monumental work.
Skip it if you're offended by scenes of explicit hardcore. It's evident on the look of the actors faces that it's all in good fun, though.
All in all classic Franco.