Short story originally published in the hardcover "End of the Game and Other Stories". Roberto Michel opens his story not by telling what happened but by mulling over how it should be told and why it must be told. Once he decides that “the best thing is to put aside all decorum and tell it, ”he recounts the events of his Sunday morning stroll along the Seine. Blow-up was the basis for Michelangelo Antonioni's film of the same title.