The Randolph Carter Mythos

The Statement of Randolph Carter is narrated in flashback by Carter while being interrogated by the police, who suspect him of murdering Harley Warren. Carter and his friend Harley Warren investigate a mysterious crypt in an ancient abandoned cemetery. "The Unnamable" begins with Carter in conversation with his friend Joel Manton, principal of a New England high school, discussing the supposedly mythical creature that bears the story's name.
The tale is set in a seventeenth-century cemetery as evening falls. Initially, Manton is skeptical and ridicules Carter for thinking that such a being may be possible. As darkness encroaches - and as Carter's descriptions become more detailed and supported by facts - his flippant dismissal gradually gives way to fear. The Dream-Quest of Unknown Kadath - one of Lovecraft's longest tales - follows Carter for several months searching for the lost city of his dreams.
The story reveals Carter's familiarity with much of Lovecraft's fictional universe. Carter is also shown to possess considerable knowledge of the politics and geography of the dream world and has allies there. After an elaborate odyssey, Carter awakes in his Boston apartment, with only a fleeting impression of the dream world he left behind, though he now knows what the lost city actually is. "The Silver Key" - perhaps the most overtly philosophical of Lovecraft's fiction - finds Carter entering middle age and losing his "key to the gate of dreams." No longer is Carter able to escape the mundane realities of life and enter the Lovecraftian dreamworld that alone has given him happiness.
Wonder is gone and he has forgotten the fact that life is nothing more than a set of mental images, where there is no fundamental distinction between dreams and reality and no reason to value one above the other.