The open book lay flat between us, with the picture staring re-pulsively upward.
As the old man whispered the words "more the same" a tiny splattering impact was heard, and Something showed on the yellowed paper of the upturned volume.
I thought of the rain and of a leaky roof, but rain is not red. —H.P. Lovecraft, The Picture In The House
In Lovecraft’s stories, the protagonist usually learns Mythos magic by finding and following written instructions. The volumes of arcane lore mentioned by the Lovecraft Circle of writers represent the intellectual invasion of the Cthulhu Mythos.
In particular, these ancient manuscripts and suppressed publications included recipes for the admission (or return!) of the Great Old Ones and the Outer Gods, as described in vivid detail in Lovecraft’s classic story The Dunwich Horror.
At least by implication, such writings also indicated how to force away or dispel those dreadful entities. It takes time to learn, even from textbooks that have been carefully written and specially laid out just for that purpose.
Studying the crabbed, idiosyncratic, and infinitely more difficult Mythos books takes much more time and dedication.
These musty, thick books are often clumsily scribed by men whose sanity has long since been erased by the horror of their experiments, trials, and conjectures. The present day apparatus of scholarship does not exist in such books.
There are no indices, no glossaries, no tables of contents, and no careful definitions. There may not be numbered pages, chapters, paragraphs, punctuation or even breaks between words.
Some tomes might best be described as the ravings of mad men—yet to the seeker of dark knowledge, such texts hold wondrous insights and power.
Many manuscripts are not even in a known alphabet— some are older than time, in languages long lost; others are written in occult ciphers to stymie witch-finders or the Inquisition, and now must be cracked before the would-be reader can ponder the sinister truths they conceal.
Even if a sorcerer wrote for others who were familiar with the arcane and occult, the writing was for adepts and cultists, not laypersons. Strange terms and ideas would be
written with no explanation. Valuable annotations might be made by a succession of owners, each perhaps in a different language or with a different aim, and some inscribed in error.
Many Mythos tomes are ancient and must be handled with care. Some are delicate and liable to crumble to dust if the reader doesn’t wear thin gloves and turn the pages with padded forceps. Some whisper that certain tomes are more than merely pages bound in leather; that they are "living" things, intent on sowing their evil taint on the unwary and acting as direct conduits to the horrors of the Outer Gods.
Only in the present does the technology exist with which to make quick and accurate copies.
