He talked of his dreams in a strangely poetic fashion; making me see with terrible vividness the damp Cyclopean city of slimy green stone - whose geometry, he oddly said, was all wrong - and hear with frightened expectancy the ceaseless, half-mental calling from underground: "Cthulhu fhtagn", "Cthulhu fhtagn."
...he dwells only on broad impressions of vast angles and stone surfaces - surfaces too great to belong to anything right or proper for this earth, and impious with horrible images and hieroglyphs. I mention his talk about angles because it suggests something Wilcox had told me of his awful dreams. He said that the geometry of the dream-place he saw was abnormal, non-Euclidean, and loathsomely redolent of spheres and dimensions apart from ours. Now an unlettered seaman felt the same thing whilst gazing at the terrible reality.
God rest them, if there be any rest in the universe. They were Donovan, Guerrera, and Angstrom. Parker slipped as the other three were plunging frenziedly over endless vistas of green-crusted rock to the boat, and Johansen swears he was swallowed up by an angle of masonry which shouldn't have been there; an angle which was acute, but behaved as if it were obtuse.
(Quotes from "The Call of Cthulhu")