Among the different literary manifestations that have proliferated in both strands of Río de la Plata, the fantastic short story has been one of the most outstanding. Uruguay and Argentina have been the birthplace of many excellent novelists, poets and playwrights whose names will live forever in the history of Latin American and world literature, but the most studied and most relevant authors of this region have been those who devoted their words to short stories, and within them, those who dabbled in the fantastic genre. It is not easy to establish a reason why this kind of literature was more intense in the Río de la Plata than in the rest of Latin America, perhaps there is no definitive explanation to clarify this fact. Julio Cortázar said once that, possibly, this proliferation was due to the fact that the surrounding reality of the countries of the Río de la Plata is much poorer than the rich tropical environment surroundings of the countries that are located in the northern side of the continent. It is a possibility to which we must add at least another reason, more relevant in my opinion: the literary influences that the authors of the early and mid-20th century from Río de la Plata had. Among the most notorious influences, some of them openly recognized by different authors from that region, we can highlight the North Americans Edgar Allan Poe and Henry James (though James, almost in the end of his life, got the British nationality); we can also highlight the influence of German writer Theodor Amadeus Hoffman; Czech Republic's Franz Kafka; France's Jules Verne; Ireland's Charles Maturin; Great Britain's Thomas de Quincey, Ann Radcliffe, Mary Shelley, Herbert George Wells and Keith Chesterton, among many other influential but less noted authors. The fantastic vein within literature is as ancient as literature itself. If we wanted to establish the origin and development of this literary line, we would have to go back to classical myths, go through some medieval literary manifestations, then follow the path of chivalric novels, and also take a look at some romantic and gothic stories. But if we wanted to theorize about that literary line, which has been present in all periods of time and has been present in many diverse literary manifestations, we would have to find out what they have in common; how, for example, a classic myth and a gothic novel are related, or how those manifestations are related to a story by Leopoldo Lugones. The answer to this question would be: the disturbing strangeness. The works in the Fantastic genre try to show a different reality than the historically recognizable reality. The facts and phenomena considered fantastic literature oppose to the natural laws, they do not imitate the reality, but they create other alternative realities that overcome or surpass what is credible or recognized as real. Of course, these supernatural elements are way different in a mythological story than in a modern civilization's story, where the explanation of that "other reality" does not have an answer linked to divinities, but to rationality and science, as long as it can be explained by them. This has led some theorists to delimitate the fantastic, to establish a more precise definition of a term that, as I mentioned before, has been used to put works with different styles and characteristics in the same bag.