Lovecraft H.P. 
The Dreams in the Witch-House [EPUB ebook] 

This story is about the bizarre dreams of Walter Gilman, a young man from Haverill, a student at Miskatonic University, located in the fictional city of Arkham, Massachusetts. Young Walter, taken from his mathematical studies and the ghostly folklore of the city, rents the room where the old witch, Keziah Mason, lived, who escaped the stake through strange lines drawn with a red liquid, probably blood, on the wall of his cell. in 1692. At the time not even Cotton Mather, the great inquisitor of witch hunts in colonial New England, could interpret these diagrams; on the contrary, Walter assumes that they are the key to travel through space and dimensions, and this is precisely the reason that drives him to undertake mathematical research accompanied by reading books such as the abhorred Necronomicon. At the beginning of the story, the protagonist suffers from a mild cerebral fever, and furthermore his hearing has sharpened disproportionately, so much so that the ticking of the clock seems like a cannon shot. But, behind this apparent patina of normal noises, Walter perceives, barely audible even for his almost magical ability, sounds that disturb him more than the scrabbling of mice in the wall, more deliberate than casual for him. From here starts a story halfway between nightmare and surreal, with Walter at the mercy of the witch Keziah and her familiar, Brown Jenkin, a monstrous hybrid with the body of a mouse and the face and hands of humans, who finally force him to sign a diabolical contract with The Black Man, one of the multiple forms of the god Nyarlathotep. However, these dreams are rather fragmented and confused, and moreover they clash with his seemingly unshakable skepticism. However, his sleepwalking is undeniable, confirmed by the tenants of the condominium where he lives and his dreams coincide horribly with the discoveries of the following day (an alien statuette, a bite on the wrist). The end of the protagonist, after his refusal to sacrifice a child on Walpurgis night, and after killing the witch in the ensuing scuffle, is terrible: Brown Jenkin will devour his heart from the inside, in front of the helpless gaze of his colleague and roommate Elwood. Only two years after her death, the remains of the witch, Brown Jenkin and the numerous children sacrificed over the centuries by the satanic cult will be found in the attic, which in the meantime collapsed due to bad weather.