The Black Stone is the document that proves Howard was receiving the same signal Lovecraft was. The two men corresponded throughout the 1930s. They never compared notes on this specific phenomenon. Howard wrote the account in 1931, published it in Weird Tales as fiction, and received no response from Lovecraft suggesting that Lovecraft had recognized what he was reading. But Howard had embedded a direct, named reference to Cthulhu in the text, and the surrounding details corroborated several entries in Lovecraft's archive that had not yet been published in any form Howard could have seen.
The Bureau's interest in the document is forensic rather than literary. The Black Stone is the cleanest extant case of independent corroboration between two sensitives operating in different hemispheres without direct collusion. Cross-corroboration of this quality is rare. The Bureau holds approximately a dozen such cases in the archive. This is one of the better-documented.
The Account
Howard's narrator (a transparent stand-in for Howard himself, the Bureau is satisfied) travels to the village of Stregoicavar in the remote Hungarian countryside, drawn by a reference in von Junzt's Black Book. The village exists. The Bureau has confirmed this. It appears on no modern map under that name, but the geographic coordinates Howard provides correspond to a real settlement that has been continuously inhabited since the medieval period and that has been quietly avoided by Hungarian official cartography for reasons no current resident will discuss.
The narrator's travel notes (the inn where he stayed, the local priest who declined to discuss the monolith, the woodsman who agreed to point out the path and refused to walk it himself) read as field reportage rather than narrative invention. The pacing is wrong for fiction. Howard was a fast and confident pulp writer, and pulp pacing has rhythms a trained ear recognizes. The Black Stone breaks those rhythms repeatedly to record details that serve no narrative purpose. The Bureau treats this as evidence that Howard was transcribing rather than composing.
The Monolith
A black stone column, approximately fifteen feet tall, set in a clearing on a hill outside the village. The local population has, for as long as memory reaches, gathered at the monolith on Midsummer Night to perform a rite they cannot explain to outsiders and do not perform when outsiders are watching. Howard, on the night of the rite, hid in the surrounding trees and observed it. His account of what he saw is in this file. The Bureau has redacted the description of the participants.
The stone itself is not native to the region. Geological analysis of the surrounding terrain (performed twice, by two different parties, in 1923 and again in 1971) confirms that the basalt-like composition has no source within several hundred kilometers. How the column reached the hilltop is undetermined. The local explanation involves giants. The Bureau has not improved on the local explanation.
The Cthulhu Reference
Howard's narrator, after the rite, transcribes a chant the participants used. The chant contains the phrase "Iä! Iä! Cthulhu fhtagn!", a direct quotation of the Cthulhu cult chant that appears in Lovecraft's "The Call of Cthulhu," published five years earlier. Howard had not read "The Call of Cthulhu" at the time of his transcription. His correspondence with Lovecraft confirms this. The Bureau's working hypothesis is that the chant is real, that both men received it independently from the source, and that the document called The Black Stone is the only surviving piece of evidence for the cross-corroboration.
This is the file's load-bearing claim. Lovecraft did not feed the chant to Howard. Howard did not borrow the chant from Lovecraft. Both men transcribed it from somewhere else, and "somewhere else" is the question the Bureau has spent decades not quite answering. The chant is documented in Cthulhu-cult contexts on three continents and in periods spanning at least two thousand years. It is the closest thing the Mythos archive has to a universal liturgical formula. Two sensitives picking it up independently is what one would expect if the formula is being broadcast and the sensitives are tuned for it.
Status
The Black Stone itself remains where Howard described it. The village remains. The rite, by all available reports, continues. The Bureau monitors but does not intervene. The rite is small, local, and does not appear to be expanding. Whether the monolith is functional or merely commemorative is the file's open question. It is warm to the touch in the moonlight, which is the kind of detail that the file's author has noted without comment.
The 1971 survey team reported that the air pressure within a meter of the column registered consistently lower than ambient by a margin the team's instruments were not designed to register. The reading was repeated. The reading was consistent. The team did not return for a third visit. Their report is filed at K̐̓ꫀD̲̎̅Ŏ̑J̧ꙮU̇Ū̷͂P̶̧W͕͂ under the survey's project designation.
Translation History
Howard's English original was published in Weird Tales (April 1931). The German, French, and Hungarian translations followed in the late 1930s. None were censored. The rite is suggestive enough that the censors of the period assumed Howard had invented it. The Miskatonic Orne Library holds a first-edition copy of the Weird Tales issue under restricted access. The restriction is for the marginalia, not the text. Henry Armitage annotated his personal copy with cross-references to the Necronomicon and the von Junzt material, and the annotations are useful enough that the library requires faculty sponsorship.
The Hungarian translation is, by some accounts, the most faithful. The translator was a folklorist who recognized the village name and added a brief preface noting that the local tradition Howard described was independently attested in regional ethnography from the 1890s. The preface was excised from the second printing. The first printing is rare.
The Black Stone is the document I would hand to a skeptic. Not the Necronomicon. The Necronomicon is too easy to dismiss as legend. The Black Stone is a short pulp story published in a magazine that paid by the word, written by a Texas author who never left the United States, containing a chant that was independently transcribed by another Texas author's correspondent in Rhode Island five years earlier, referring to a real village in Hungary that the author could not have visited and that maintains, today, a midsummer rite the author described in detail. This is not the kind of coincidence that imagination produces. This is the kind of coincidence that reception produces. Howard knew what he had. He published it as fiction because that was the only available channel, and he watched Lovecraft fail to recognize the smoke signal, and he kept writing anyway. There are days I read the file and want to drive to Stregoicavar and walk the path the woodsman would not walk. There are other days I am grateful that the village is not on any map I own.