The trio of earth-men, hard-bitten adventurers who disdained the services of Martian guides, had started five days before from the outpost of Ahoom, into the uninhabited region called the Chaur. Here, in the beds of great rivers that had not flowed for cycles, it was rumored that the pale, platinum-like gold of Mars could be found lying in heaps, like so much salt. If fortune were propitious, their years of somewhat unwilling exile on the red planet would soon be at an end. They had been warned against the Chaur, and had heard some queer tales in Ahoon regarding the reasons why former prospectors had not returned. But danger, no matter how dire or exotic, was merely a part of their daily routine. With a chance of unlimited gold at the journey's end, they would have gone down through Hinnom.A sand storm (or "hell-twister") called a zoorth by the native Aihais forces the three men into a cave for shelter. While there, they here a strange sound like "a sharp rustling and rattling as of metal dragged over rock; and also it was somehow like the smacking of myriad wet enormous mouths." One of the men, Bellman dismisses concern that these sounds might have been made "one of the millipedal underground monsters, half a mile long, that the Martians tell about" as "fairy-tales," as the Chaur is "devoid of life save perhaps "rival gold-hunters from the Earth." Plus, even if he's wrong, "We've got our revolvers."
Since the zoorth will rage for at least half an hour, the three men start to explore the cave, hoping to find "a few violet rubies or amber-yellow sapphires, such as are sometimes discovered in these desert caverns." They find no gems but they do find an immense chasm.
Bellman was leading the way. Suddenly his torch revealed the verge of a precipice, where the olden channel ended sheerly and the shelves and walls pitched away on each side into incalculable space. Going to the very edge, he dipped his pencil of light adown the abyss, disclosing only the vertical cliff that fell at his feet into darkness with no apparent bottom. The beam also failed to reach the further shore of the gulf, which might have been leagues in extent.Discovering that an ancient road had been hewn from the face of the cliff, spiraling downward around the chasm, the three adventurers proceed along "our road to Hades." Eventually, the silence of the place is broken by
the same peculiar long-drawn sound or combination of sounds which they had heard in the outer cavern. It suggested other images now: the rustling was a file-like scraping; the soft, methodical myriad smacking was vaguely similar to the noise made by some enormous creature that withdraws its feet from a quagmire.Their confidence shattered, the Earth men decide to retrace their steps and return to the surface to wait out the storm. Unfortunately, they find the way blocked by "an array of whitish creatures, three abreast." Shining their flashlights on them, they what stands before them.
The creatures, who stood perfectly motionless and silent, as if awaiting the earth-men, were generically similar to the Aihais or Martian natives. They seemed, however, to represent an extremely degraded and aberrant type, and the fungus-like pallor of their bodies denoted many ages of underground life. They were smaller too, than full-grown Aihais, being, on the average, about five feet tall. They possessed the enormous open nostrils, the flaring ears, the barrel chests and lanky limbs of the Martians -- but all of them were eyeless. In the faces of some, there were faint, rudimentary slits where the eyes should have been; in the faces of others, there were deep and empty orbits that suggested the removal of the eyeballs.Smith originally entitled this story "The Eidolon of the Blind" in reference to its conclusion, after the eyeless Aihais take the three humans deeper into the caverns to reveal the source of the strange noises they had been hearing. When it appeared in Wonder Stories, it bore yet another title, "Dweller in Martian Depths," and much of its text was changed without the knowledge or participation of CAS. It did not appear under its current title until 1960, when many of the textual changes were also reversed.
I personally prefer "The Vaults of Yoh-Vombis" to this story, mostly because the former tale maintains a more consistent "scientific" feel to it. That is, it's unambiguously a work of science fiction and, somehow, that makes its ending all the more horrific for me. "The Dweller in the Gulf," though not a fantasy as such, veers toward fantasy in my view, and that somewhat weakens its horrors, which feel less stark as a consequence, if that makes any sense. Regardless, "The Dweller in the Gulf" is creepy, brooding tale and one of Smith's finest works. It also enjoys the distinction of being short and to the point, losing none of its atmosphere or punch as a consequence of its relative brevity. Indeed, it probably works better precisely because it is so succinct.