The Devil's Day by James A. Blish
Was first published as two books, Black Easter and The Day After Judgment but i review them as one book on my list. They are about a weapon entrepreneur that take the help of a black magician to perform a magical experiment. It do not go well, it never does, and the lower circles of hell rise to the earth and the whole world turn into one large nuclear battlefield.
This is short story that take up to many pages and the end is so sudden and boring that it almost feel that the writer also gave up. I guess it was impressive to list all the names of the fallen angels and what they look like when the book was published in 1968. Sadly it does add nothing to the story and now that i can Wikipedia them it gets even more tiresome to read.