At The Mountains of Madness is one of H.P. Lovecraft’s most influential novels. Written in 1931, it presents the first-person narration of Dr. William Dyer, a geologist at Miskatonic University. Dyer is a survivor of a paleontological drilling expedition to the Antarctic and he tells the reader that he is telling his story in order to dissuade another group of adventurers and scientists (the Starkweather-Moore expedition) from visiting the icy continent lest they accidentally unleash ancient horrors on modern humanity.
In the course of the story, Dyer reveals that their leader Dr. Lake took men ahead in search of fossils and found a massive mountain range taller than the Himalayas. They also discovered an underground cavern system filled with strange creatures (the Old Ones) that the scientists think are fossilized but which are actually in a state of suspended animation. The scientists take the Old Ones back to their camp for examination despite their sled dogs reacting violently towards them; Dyer and his companions get their reports over the radio.
When Lake’s party goes ominously silent, Dyer’s party goes to investigate. They find Lake and his men gruesomely dead and the Old Ones either carefully buried or missing. A man named Gedney is also missing; Dyer and his companion Danforth go searching for him in an airplane. Past the huge mountains, they find the vast, ancient stone city of the Old Ones and glimpse an even taller mountain range beyond it. They explore the ruins and find murals depicting the Old One’s alien origins and long rein on earth before humans evolved, Gedney’s body carefully stowed as a scientific sample, giant albino cave penguins, and a fearsome shoggoth that kills the surviving Old Ones and pursues Dyer and Danforth out of the city.
It really does read like the travelogue of a pedantic college professor, and we get pages and pages of descriptions of fossils and geology and landscape and history. The emphasis on the world building sells the reader on the believability of the story through the exhaustive details ... but that in combination with Dyer’s academic diction saps the tension from parts of the novel. It might be a bit of a slog for those used to faster-paced narratives. (But this novel would be a good piece to compare and contrast with Dan Simmons’ excellent novel The Terror, which features an elaborate, frightening arctic setting described masterfully.)
That said, I found it tremendously useful precisely because of its elaborate backstories. It’s an encyclopedia of the histories of many of the most popular Lovecraftian monsters. So my take is that this novel is a must-read for any writer who wants to write weird fiction or horror based on Lovecraft’s settings.