Here the story seems to need careful perusal and thought above the rather simple narrative plot. A man whose family is both Argentinian and German, plans to leave his job in Buenos Aires eventually to live at his homestead, a ranch down in the South.
He reads a few stories of One Thousand and One Nights, takes ill after hitting his head on a newly painted door, ends up with septicemia in a hospital for a long time, is released and stopping to collect some things at his apartment, takes a train for the South and his family home. He reads a bit more of the book, but is generally happy to see the land going by from his window seat. He is told by the conductor that he must get off at a stop prior to that which he’d planned to reach his destination by carriage. He gets off at a station, goes to a general store where he is bullied into a knife fight, for which he is unprepared but an old gaucho tosses him a weapon and he is compelled to go out into the street and face down his challenger. Oddly enough, he is not completely unhappy with the possibility of his death, perhaps thinking of his grandfather’s own proud struggles in obtaining the land.
They went out and if Dahlmann was without hope, he was also without fear. As he crossed the threshold, he felt that to die in a knife fight, under the open sky, and going forward to the attack, would have been a liberation, a joy, and a festive occasion, on the first night in the sanitarium, when they stuck him with the needle. He felt that if he had been able to choose, then, or to dream his death, this would have been the death he would have chosen or dreamt. (p. 174)
In the prologue to these last nine stories Borges suggests that there is meaning beyond the narrative here (duh!). After meandering through his labyrinth of stories and picking up clues here and there (or at the same place simultaneously) I am suspicious of all that has occurred to the character since leaving his bed at the sanitarium. Memory = Dreams = Unreality.
There is a carefully outlined family history of the freedom of the plains, the land steeped in memories down south that still live on, despite the cosmopolitan atmosphere of the big cities up north, such as Buenos Aires. There appears to be a borderline drawn between two times, two lives, and Borges himself hints at a melding of the two:
Tomorrow I’ll wake up at the ranch, he thought, and it was as if he was two men at a time: the man who traveled through the autumn day across the geography of the fatherland, and the other one, locked up in a sanitarium and subject to methodical servitude. (p. 170)
My guess is that he doesn’t hit the street outside and face a fight for his life with a knife he barely knows how to hold properly. But this thought is preferable to the reality of his existence.