Sorcery & Sancity ~ The Public Domain Works Of Arthur Machen For Your Sword And Sorcery Campaign

You Can Get His Wonderful Book
The House of Souls and Within You'll Find 'The White People "
Novella
HERE

 Once upon a time when I was living in Boston back in nineteen ninety something I had a copy of this very book. The book is now ash but the author Arthur Machen and his works stayed with me. Machen wrote of Occult survivals in dark places and weird dimensions far beyond our own.
 He was one of the spiritual fore fathers of both  HP Lovecraft and his circle especially Robert Howard.
 It is only recently that I've reread this story in this collection from Chaosium.  The short story has an incredible atomshpere that seems to hint at survivals from beyond time when the cycle of the supernatural still seemingly haunted the countryside of England. Its horrors are more subtle and atmospheric then say the Great God Pan another classic of Machen and the other works of Machen. See below. 

 The plot according to Wiki :
A discussion between two men on the nature of evil leads one of them to reveal a mysterious Green Book he possesses. It is a young girl's diary, in which she describes in ingenuous yet evocative prose her strange impressions of the countryside in which she lives, as well as conversations with her nurse, who initiates her into a secret world of folklore and ritual magic. Throughout, she makes cryptic allusions to such topics as "nymphs", "Dôls", "voolas," "white, green, and scarlet ceremonies", "Aklo letters", the "Xu" and "Chian" languages, "Mao games", and a game called "Troy Town" (the last of which is a reference to actual practices involving labyrinths or labyrinthine dances^[1]). The girl's tale gradually develops a mounting atmosphere of suspense, with suggestions of witchcraft, only to break off abruptly just at the point where a supreme revelation seems imminent. In a return to the frame story, the custodian of the diary reveals that the girl had "poisoned herself—in time", making the analogy of a child finding the key to a locked medicine cabinet.^[2]


 Read more about the father of the modern horror story right over
HERE

 Using The White People For Your Old School
Sword and Sorcery Campaign 

According to Wiki :
The story has frequently been reprinted, and scholars and devotees of supernatural fiction often cite it as a classic of the genre. E. F. Bleiler, for example, wrote that the narrative in the Green Book "is probably the finest single supernatural story of the century, perhaps in the literature",^[5] and S. T. Joshi has called the diary "a masterpiece of indirection, a Lovecraft plot told by James Joyce".^[6] H. P. Lovecraft himself wrote that "Machen's narrative, a triumph of skilful selectiveness and restraint, accumulates enormous power as it flows on in a stream of innocent childish prattle"
 The Green Book as a framing device for the story is one that I've used time and again in D&D game adventures. The PC's stumble upon a book, a scroll, or other piece of parchement  written by some innocent fool who has dallyed with powers from beyond.
The PC come into contact with these powers and suddenly are thrust into a world of  horror and danger beyond their kin. Machen creates the great "After The Fact Narrative" which can be used for any number of sword and sorcery style adventures. These style of adventures often have survivals from ancient times holding seemly innocent locations in the thrall of horrors from beyond. They are often times the home of at least a small cult or the outpost for a greater more dangerous menace which holds the region in question in its grasp. 

 You can download
The Three Imposters
HERE
 The book 'The Three Imposters' by contains even more tales that are perfect for crossing the boundries between tales of horor and sword and sorcery.

• The Three Impostors (1895) — A novel incorporating several short stories, including "The Novel of the White Powder" and "The Novel of the Black Seal", which have often been anthologised separately. Centers on the search for a man with spectacles.
  • "The Novel of the Black Seal" — A precursor of H. P. Lovecraft in its subject matter—the protagonist gradually uncovers the secrets of a hidden pre- and non-human race hiding in the Welsh hills, and the true nature of a hybrid, idiot child fathered by one of them.
  • "The Novel of the White Powder" — A man's behavior takes a strange turn after he starts taking a new prescription. His sister doesn't know if this is a good thing or a bad one.
• "The Red Hand" (1895) — A story featuring the main characters from The Three Impostors. It focuses on a murder performed with an ancient stone axe.

The Three Imposters concerns the following from wiki once again:
  The novel incorporates several inset weird tales and culminates in a final denouement of deadly horror, connected with a secret society devoted to debauched pagan rites. The three imposters of the title are members of this society who weave a web of deception in the streets of London—retailing the aforementioned weird tales in the process—as they search for a missing Roman coin commemorating an infamous orgy by the EmperorTiberius and close in on their prey: "the young man with spectacles".
"The White Powder" for instance could be used as the first signs of a witch's cult operating in Hyperborea for Astonishing Swordmen and Sorcerers of Hyperborea.
:"The Red Hand" is the perfect framing device for the use of an artifact or magic item from the dungeons of Hyperborea with some citystate murder. Suddenly the PC's have to unravel a mystery, a cult, and its connecto to the magic item or artifact.
The Novel of The Black Seal could be used as the basis for a cult of witches and thier god operating within the hills of Hyperborea and the weird projeny that are lurking within Hyperborean society.  I've used these works over and over again. Thanks to Jack Shear's Tales of The Grotesque and Dungeonsque I've incorporated them into several Flintlock and Matchlock style games as well. Machen is easily adaptable into a wide variety of  retroclone genre games and their way to many of his works to go into in one simple blog entry.