"The Immortal" is the title of a short story by noted Argentine author Jorge Luis Borges. He published it in the collection El Aleph, 1949. The story tells about a character who mistakenly achieves immortality and then, weary of a long life, struggles to lose it and writes an account of his experiences.
The story consists of a quote, an introduction, five chapters, and a post script.
The introduction takes place in London in the first part of June 1929. Herein the following five chapters are purported to have been found in the last of six volumes in small quarto (1715-20) of Alexander Pope's Iliad.
The story is an autobiographical tale told by a Roman soldier, Marcus Flaminius Rufus, during the reign of the emperor Diocletian. During a sleepless night in Thebes, Egypt, a mysterious man, exhausted and wounded, seeks refuge in his camp. Just before dying, he tells Rufus about a river whose waters bestow immortality on whoever drinks from it. The river is next to a place called the City of the Immortals. Determined to find it, Rufus sets out for Africa with his soldiers. The harsh conditions of the trip cause many of his men to desert. After hearing that the remaining soldiers are planning his death, Rufus flees and wanders through the desert.
Rufus wakes up from a nightmare to find himself tied up in a small recess on the side of the mountain. Down below, he spots a polluted stream and jumps down to drink from it; wounded, he falls asleep. Over the next few days, he begins to explore the area, which he discovers to be the famed City of the Immortals. The city itself is abandoned, but a race of troglodytes, or cave-dwellers, live on the outskirts.
The City of the Immortals is an immense labyrinth with dead-end passages, inverted stairways, and all manner of chaotic architectural structures. Rufus, horrified and repulsed by the city, describes it as "a chaos of heterogeneous words, the body of a tiger or a bull in which teeth, organs and heads monstrously pullulate in mutual conjunction and hatred."