The somewhat curious reference to Nyarlathotep toward the end—when the narrator, crazed by what he has seen, believes that the rats are “determined to lead me on even unto those grinning caverns of earth’s centre where Nyarlathotep, the mad faceless god, howls blindly in the darkness to the piping of two amorphous idiot flute-players”—ties the story, however tangentially, to the Cthulhu Mythos. This baleful god, emerging out of the depths of Egypt and bearing the likeness of a Pharaoh, was first cited in the prose-poem “Nyarlathotep” (1920), which was itself based on a dream Lovecraft had only a short time before. In that earlier story Nyarlathotep is by means faceless, and Lovecraft may have been thinking of the hideous night-gaunts—creatures he also dreamed, as early as 1896, when he was five years old—who are indeed (as he states in a letter) “black, lean, rubbery things with bared, barbed tails, bat-wings, and no faces at all!”
The story had a peculiar and unexpected sequel. Shortly after writing it in the fall of 1923, Lovecraft discussed with Long one possible drawback about using some Celtic words (lifted, as I’ve mentioned, directly from Fiona Macleod’s “The Sin-Eater”) at the end of the story: “The only objection to the phrase is that it’s Gaelic instead of Cymric as the south-of-England locale demands. But as with anthropology—details don’t count. Nobody will ever stop to note the difference.”
Lovecraft was wrong on two counts. First, the notion that the Gaels arrived first in Britain and were driven north by the Cymri is now seriously doubted by historians and anthropologists; second, someone did note the difference. When “The Rats in the Walls” was reprinted in Weird Tales for June 1930, a young writer wrote to the editor, Farnsworth Wright, asking whether Lovecraft was adhering to an alternate theory about the settling of Britain. Wright felt that the letter was interesting enough to pass on to Lovecraft. It was in this way that Lovecraft came into contact with Robert E. Howard. Much of their early correspondence, which lasted until Howard’s death in 1936, concerned arcane points of history, ethnography, and related matters. Over the course of their six-year acquaintance they generated letters that are among the richest and most revealing that either author wrote.
“The Rats in the Walls” has rightly been one of Lovecraft’s most popular stories. Readers have sensed that it is not only a nearly flawless instance of the short story but one that features a depth and complexity that foreshadow the even more substantial tales of his last decade of writing."
