This novella is a real delight! I love all things Lovecraftian, with or without the inherent racism of the original, but fortunately, almost EVERY hand put to the task of building upon the mythos has recreated it into something egalitarian and deep while still retaining the rich, rich imaginings. 
 This continues the quest within the Dreamland but from the point of view of a middle-aged teacher of mathematics from *within* this other world, helping out a student from our world who had fallen in love with a man in the Dreamland who, if allowed to continue, would set all the gods of creation on a tear to destroy everything because the two SHALL NOT mix. 
 My favorite bits are the fact that this woman doesn't have any special skills. She settled down from her wandering days to become a prof but still dropped it all to go on a long and wonderful quest filled with monsters and demons and whatnot with nothing more than her perseverance. :) 
 Imaginative. So imaginative. This continues Lovecraft's original, sure, but Kij Johnson flows deep within these rivers that are at once familiar and very unfamiliar, evoking a blase attitude to things that are richly disturbing and strange, evoking awe with simple concepts like the number Pi that *doesn't* change its value, and so many other cool bits with Ghasts and Gouls and Gaunts. 
 After reading this I'm thrilled and pretty well amazed and totally on-board with reading anything else this woman has ever written. Anything that can evoke awe in this old reader has got to be cherished. 
 This one might make my top pick for the Hugo Novella category for this year. It's either that or Every Heart a Doorway