A man stabbed to death is haunted by his memories and fantasies while dying alone.

A voice, warm and heartbreaking, that of Brisseau himself, coils over black and white images. The tone was set very quickly: "To wake up is to be born again in the world of despair." 'On Sunday afternoon' is a film all at once clinical and theoretical on melancholy in the strong sense of the famous "black bile" of the Greeks whose author seems to want to make a complete turn, from his tragic dimension to his psychological dimension, even ending his film with a long quote from Freud's 'Mourning and Melancholia'.

Paris, Latin Quarter, May 1968. Images of barricades and police movements in the street. In his bedroom, on his bed, a young man indulges in daydreams that invade the whole space.