| This very unusual work of fiction is a proof of a technical mathematical fact in the form of a fantasy novel.
The specific claim it proves is that a locally L-bilipschitz mapping between uniformly Ahlfors q-regular, complete and locally compact path-metric spaces X and Y is an L-bilipschitz map when Y is simply connected.
The author worked on this subject as a mathematics PhD student in Finland and decided to present it as a story about map-making dwarves living in a world where a mysterious event has changed the geometry of physical space, rendering 2-dimensional maps useless. The story can read for paragraphs as if it was a traditional fantasy novel, but then inexplicably switches to mathematical notation (including references to human mathematicians like Ahlfors and "bilipschitz").
I am not sufficiently expert in this area to judge whether this result is truly novel nor whether the proof is accurate, but I also have no reason to doubt that it is.
Thanks to Allan Goldberg for pointing it out to me when it was published in the January 2022 issue of The Journal of Humanistic Mathematics. | 
