There’s a guy named Randolph Carter. Carter has experienced a recurring dream, in which he walked through a glorious city, impossibly beautiful. The dream ends abruptly, before he’s ready for it to conclude, and it stirs up Carter’s deepest emotional memory. He suspects he knew this city in a past life, or as an infant, and furthermore, he believes that the gods intervene to keep him from experiencing the city in full. This is why, he figures, he keeps waking up whenever he tries to descend from the high plaza over the city into its streets.
He prays to these mysterious gods, both in the waking world and while asleep, but they do not answer him. Thus he makes the decision to travel as a pilgrim to the land of Kadath, “unknown Kadath in the cold waste where no man treads,” where these gods dwell in an onyx castle. There, in person, he shall petition them for access to the city of his dreams. How Carter knows where the gods dwell, and how Carter knows the gods are the responsible parties for his pain: unaddressed.
Kadath can be accessed from the land of dreams only (how Carter knows this is not addressed), and so Carter must visit the Dreamlands. His method for doing so: he dreams that he descends seventy steps to a great cavern, lit by lamps, which is itself a temple. The two priests of the temple, bearded men named Nasht and Kaman-Thah meet him and hear his plan. They warn Carter that the gods of Kadath don’t enjoy it when mortals show up from nowhere and bug them. Also they don’t know how to get to Kadath: it’s accessible from the land of dreams, but which land of dreams? The land of dreams dreamed by people who live on Earth, or the Dreamlands corresponding to other planets? It’s a foolish quest, is their basic point. That’s not even getting into the many dangers involved in long-distance Dreamlands travel. The gulf between worlds in the Dreamlands isn’t occupied by an infinite empty void, but by demons.
The description of these demons defies summary: “…that shocking final peril which gibbers unmentionably outside the ordered universe, where no dreams reach; that last amorphous blight of nethermost confusion which blasphemes and bubbles at the centre of all infinity – the boundless daemon sultan Azathoth, whose name no lips dare speak aloud, and who gnaws hungrily in inconceivable, unlighted chambers beyond time amidst the muffled, maddening beating of vile drums and the thin, monotonous whine of accursed flutes; to which detestable pounding and piping dance slowly, awkwardly, and absurdly the gigantic Ultimate gods, the blind, voiceless, tenebrous, mindless Other gods whose soul and messenger is the crawling chaos Nyarlathotep.”
Lovecraft lays it on a little thick at time but he’s still way better than Malory. Only three people in all of history ever successfully visited the interstellar gulfs and returned, and of the three, two came back crazy. But Carter refuses to listen to the priests’ warning. He descends from their cavern down another flight of steps, eighty steps down to the Gate of Deeper Slumber, and emerges into the Dreamlands proper, in an enchanted forest.