H. P. Lovecraft was born August 20, 1890, 125 years ago. He's most famous for his story The Call of Cthulhu. Here's an excerpt.
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. .... 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 shouldnt have been there;
an angle which was acute, but behaved as if it were obtuse.
We have various non-Euclidean Demonstration, mostly using the Poincaré disk. Here's a challenge. Use a small red dot to indicate Parker. Then use non-Euclidean geometry of some sort to put Parker in a dangerous situation.