The subplot involves Damiel visiting the set of the Peter Falk's latest movie. Although humans cannot see angels, he seems to have an innate ability to detect their presence. Falk has a secret that he shares with the angel in order to convince him to turn human.
The angel eventually does give up his immortality and then must deal with human emotions and suffering. As a human, he bleeds for the first time, sees in color (the first half of the movie is filmed in sepia), and tastes food and drinks coffee. He meets Peter Falk has his human self and also arranges to run into Marion at a music concert.
The main theme of the film is what it means to be human. It is a mixture of philosophizing about the nature of humanity and an old-fashioned love story. It is a film that serious movie-goers will enjoy for its dream-like quality and unconventional story-telling techniques.