The Powder of Ibn-Ghazi is one of the few items in this directory that works for the investigators rather than against them. It makes invisible things visible. Briefly — a few minutes at most — but that has proven sufficient to kill entities that would otherwise be undetectable, and the countermeasure has been used at least twice in the documented record with successful outcomes. The formula is in the Latin Wormius Necronomicon. The ingredients are V͊͢G͞ĠH̀E̓L̐ꙮꫀ.

This is the file the Bureau most often gets requests to share, and the file it most often refuses to share in full. The reason is in the ingredients section, which is short.

Origin

Ibn-Ghazi was a twelfth-century Maghrebi alchemist whose surviving works are sparse and whose reputation rests almost entirely on this single preparation. The powder first appears in a treatise he wrote in 1156, describing it as a tool for "revealing that which walks unseen among the tents at night." The phrasing is telling. Ibn-Ghazi was not theorizing. He was solving a specific operational problem in a specific desert, and the powder is what he made to solve it.

Ibn-Ghazi died in 1163. His treatise records that the death was from natural causes. His students recorded otherwise, and his students were the ones who continued making the powder.

Transmission

The formula passed from Ibn-Ghazi's students into the broader Arabic alchemical tradition, then — via the Spanish translation movements of the twelfth and thirteenth centuries — into European hands. Alhazred had referenced it in the Necronomicon centuries earlier, drawing on a common Arabic source that predated both men, which is how Olaus Wormius knew to preserve the formula in his 1228 Latin edition.

The formula has never been printed in any uncensored form. It survives only in manuscript traditions. The ingredients list has been miscopied often enough that the majority of attempted reproductions yield nothing more useful than scented smoke. The Bureau is grateful for this. The Bureau also notes that the Wormius edition is correct, complete, and held in libraries that admit visitors with the right credentials.

The Dunwich Application

September 1928. Henry Armitage prepared the powder from the Miskatonic Wormius edition in the days before the Sentinel Hill intervention. The preparation took approximately forty hours of continuous work. Armitage's notebook records the process in clinical detail, including the three substitutions he was forced to make because the original ingredients were either unobtainable or illegal to procure through any legitimate channel. Two of the substitutions were chemical analogues. The third was — by Armitage's own description — a guess based on a marginal note in a fourteenth-century commentary.

The substitutions worked. On Sentinel Hill, the powder rendered Wilbur Whateley's twin visible long enough for the incantation to take effect. Without it, the intervention would have failed and the entity would have continued its descent toward the Dunwich farmland unimpeded. The :::thread block at the bottom of this file does not adequately convey how close that operation came to failure. Armitage knew. His notebook entry for the night of September 14, 1928 reads simply: "Forty hours of work for three minutes of sight. Three minutes was enough. Just."

Current Status

Small quantities exist. The Miskatonic Orne Library holds approximately four ounces in a vault, kept in a sealed brass container under conditions that the head librarian describes only as "appropriate." Three private collections hold smaller amounts — one in New England, one in the United Kingdom, one in a Mediterranean country the Bureau prefers not to name in this file. The preparation is time-consuming, the ingredients are difficult, and the shelf life is limited. The powder loses potency after roughly eighteen months even in ideal conditions, after which it becomes inert and slightly toxic. Nobody is manufacturing it at scale. Nobody should.

The Ingredients

The file does not publish the ingredients. This is not because they are secret. It is because each ingredient, individually, is either hazardous, illegal, or both, and the combination requires preparation steps that produce intermediate compounds which fail every safety review the Bureau could imagine performing. One of the steps releases a vapor that has been documented to cause permanent olfactory damage in trained alchemists working under protective conditions. Another requires a temperature regime that is incompatible with any modern laboratory glassware.

Anyone who genuinely needs the formula has access to the Wormius Necronomicon or to one of the surviving Arabic manuscripts. The Bureau will not do the work for them. The Bureau will, on request, confirm or deny whether a given amateur reproduction is likely to function. The answer is almost always "no."