Paolo and Carlo are good friends. The first introverted, disillusioned and intellectual, while the other is happy if shallow. Despite their differences they share accommodation. Paolo runs an “alternative” kind of library; Carlo plays the violin in a little band. Their lives go on peacefully, when suddenly Paolo falls in love with one of his a customers - Lili, an amateur actress - whom he decides to take home. Carlo doesn’t react well to the fact he’s got to share with a third person, so he comes up with a weird idea - he flirts with the new girl and manages to seduce her. Paolo thinks his best friend is now guilty of a real betrayal, while Lili is undecided: she’s attracted by both the culture of Paolo and the physical attraction of Carlo. This love triangle ends when Paolo tries to commit suicide, Carlo feels guilty and Lili leaves them both, returning to her previous life and still hoping to find her one true love.