A university student is forced, by his lack of funds, to take the only lodging he can afford. In a strange part of the city he had never seen before, on a street named "Rue d'Auseil", he finds an apartment in an almost empty building. One of the few other tenants is an old German man named Erich Zann. The old man is mute and plays the viol with a local orchestra. He lives on the top floor and when alone at night, plays strange melodies never heard before.
The short story is actually an excerpt from a letter Lovecraft wrote. It begins in the attic of an ancient house. The narrator’s companion refers to the former owner of the house and the presumably violent end that befell him. He advises the narrator not to stay after dark or touch anything, especially the small object on a table, which the companion seems to fear considerably.
In the degenerate, unliked backwater of Dunwich, Wilbur Whately, a most unusual child, is born. Of unnatural parentage, he grows at an uncanny pace to an unsettling height, but the boy's arrival simply precedes that of a true horror: one of the Old Ones, that forces the people of the town to hole up by night.
Circles and pentagrams loomed on every hand, and told indubitably of the strange beliefs and aspirations of those who dwelt so squalidly here. In the cellar, however, the strangest thing was found-a pile of genuine gold ingots covered carelessly with a piece of burlap, and bearing upon their shining surfaces the same weird hieroglyphics which also adorned the walls.
According to the tale, more than 10,000 years ago, a race of shepherd people colonized the banks of the river Ai in a land called Mnar, forming the cities of Thraa, Ilarnek, and Kadatheron (not to be confused with Kadath), which rose to great intellectual and mercantile prowess. Craving more land, a group of these hardy people migrated to the shores of a lonely and vast lake at the heart of Mnar, founding the metropolis of Sarnath.
"The Descendant" is a story fragment, believed to have been written in 1927. Lovecraft may have been referring to this attempt at a story when he wrote that he was "making a very careful study of London…in order to get background for tales involving richer antiquities than America can furnish."