The story is split up into 4 chapters:
I. The Shadow On The Chimney
The narrator, hearing tales of a "lurking fear" upon Tempest
Mountain, takes two men with him to investigate. They camp inside the
deserted Martense Mansion
as a lightning storm approaches, and feeling strangely drowsy, they all
fall alseep. The narrator wakes up to find both his companions missing,
and in a flash of lightning sees a demonic shadow cast upon the
II. A Passer In The Storm
Continuing his investigation, the narrator teams up with Arthur
Munroe, another journalist. The two find as much information as they
can on the Mansion and environs, until they find themselves trapped by
yet another storm. Bunkered in a small cabin, they witness a bright
flash of lightning. Arthur looks out the window to survey the damage.
The narrator, curious as to why Arthur is still staring out the window,
turns him to find his face chewed off.
III. What The Red Glare Meant
As the narrator digs upon the grave of Jan Martense, he describes
the history of the Martense family. Upon reaching the coffin, he
continues to dig, and subsequently falls into a subterranean burrow.
He crawls along, until he sees two eyes reflecting his torch-light in
the darkness. Yet another lightning-strike causes the tunnel to cave in
above the beast and the narrator has to dig his way to the surface. He
spots a red glare in the distance that he learns was a cabin that the
hillside squatters had set alight with one of the beasts inside.
IV. The Horror In The Eyes
The narrator continues to search for more clues, until it occurs to
him that peculiar mounds of earth lead out in lines from the Mansion.
He finds a burrow entrance in the basement as another storm approaches.
Finding a hiding place, he watches as countless creatures crawl from
the hole. He shoots the last over a clap of thunder, and upon closer
inspection, notices the creature's heterochromia and realizes that the deformed, hair-covered creature is in fact a relative of the Martense family.