The remaining, non-genre specific squares - you can read anything that is horror, mystery, suspense or supernatural that otherwise fits the square prompt.
39. Thirteen (13): any book that relates to bad luck, superstition, or the number 13, either in the title/book/series/page count. Booklist linked here.
40. A Grimm Tale: any fairy tale or retelling of fairy tales, folklore, legends, etc. Book list linked here.
41. Aliens: any mystery, horror, suspense or supernatural book that includes aliens, either here on earth, or in space. Book list linked here.
42. Creepy Carnivals: horror/mystery/supernatural set in or concerning a carnival, amusement park, or other party/festival - think Something Wicked This Way Comes by Ray Bradbury, Joyland by Stephen King or Hallowe'en Party by Agatha Christie; Book list linked here.
43. Creepy Crawlies: this is a throw back from 2016! Books with bugs, snakes, spiders, worms and other things that slither, scuttle or crawl, includes viruses and other parasites. Book list linked here.
44. In The Dark, Dark Woods: a mystery, suspense, horror or supernatural book in which the forest/woods plays a significant role, or which has a forest/woods on the cover. Book list linked here.
45. Darkest London: mystery, horror, supernatural, or suspense set in London. Book list linked here.
46. Demons: Any book involving demons, demonic possession or other such elements. Book list linked here.
47. Diverse voices: written by an author of color. Book list linked here.
48. Doomsday: anything related to the end of the world, doomsday cults, or a post-apocalypse world. Book list linked here.
49. Fear the Drowning Deep: books with sea-related elements: sea creatures, ships, and sharks. Book list linked here.
50. Full Moon: a book with an image of the moon on the cover, the word moon in the title, or where a full moon figures prominently in the story. Book list linked here.
51. Gothic: any book with significant: a genre or mode of literature and film that combines fiction and horror, death, and at times romance. Book list linked here.
52. Grave or Graveyard: Books that have a grave or graveyard on their covers, in their titles, or any book primarily set in a graveyard. Book list linked here.
53. Halloween: This is a combination of the "pumpkin" and the "halloween" squares from 2016. so, any book set on halloween or has halloween in the title or that has a pumpkin on the cover, or in the title, etc.. will work for this square. Book lists linked here: pumpkins and halloween.
54. Monsters: This square covers any crytpozoological or mythological creature that isn't a vampire, werewolf, or demon. Or zombie. Book list linked here.
55. New Release: mystery, suspense, horror or supernatural that was published after 10/31/18.
56. Read by Flashlight or Candlelight: Back by popular request! Any mystery, suspense, supernatural or horror book - the trick here is to spend an hour or so reading by flashlight or candlelight. Take a picture and share it with us, if you want to!
57. Relics and Curiosities: concerning magical, supernatural or haunted objects, such as spell-books, talismans or swords; Book list linked here.
58. Sleepy Hollow: this is the new version of set in New England, with a shout-out to that most New England of all stories, The Legend of Sleepy Hollow. Book list linked here.
59. Free square: Our friend, Poe, is back for his fourth outing!
60. Black Cat: We haven't seen this square since our first bingo game, back in 2016! Any book that has a black cat in the title, on the cover, or in the story. Book list linked here.
61. It Was A Dark and Stormy Night: This is another throwback to 2016 - any book that takes place on "a dark and stormy night." Book list linked here.