Las armas secretas
Las armas secretas (translates to The Secret Weapons in English) is a book of five short stories written by Julio Cortázar. The latter four stories appear in translation in the volume Blow-up and Other Stories (alternatively titled The End of the Game and Other Stories); the first story, "Cartas de Mamá," was published by Sublunary Editions as a stand-alone paperback in English translation by Magdalena Edwards in 2022.

Stories
"Letters from Mom": a story about an Argentine couple living in exile in Paris where they live under the yoke of a dark story that happened before leaving Buenos Aires.
"Good services" ("At Your Service" in the US translation): a mystery with a strong element of social criticism.
"The Droolings of the Devil" ("Blow-Up" in the US translation): the story that inspired the film Blowup by Michelangelo Antonioni for its digressive execution of metalinguistic narrative and lucid contemplation; (its beginning guarantees it, never will you know how it has to be told, if in the first person or in the second, using the third person plural or continually inventing forms that serve no purpose)
"The Pursuer": a homage to jazz and the creator of bebop, Charlie Parker, in which Cortázar unfurls countless musical choices, between allegories and metaphors, that reveal to the reader the author's exquisite  passion for music.
"Secret Weapons": a story centering on the conflict between Pierre and Michele, a young couple in Paris after World War II.

References

1959 short story collections
Short story collections by Julio Cortázar
Postmodern books