Cthulhu! Yog-Sothoth! Nyarlathotep! If these uncouth names suggest to you nothing more sinister than a cat trying to throw up a hairball, you have clearly passed through life untouched by the horror stories of the American pulp writer H P Lovecraft. Judged by conventional literary standards, Lovecraft could not write for toffee, and yet his weird tales, usually about reclusive New England types driven insane by the sight of these hideous and eldritch deities (the ‘Great Old Ones’, slime-dripping lurkers at the fringe of our universe), have a kind of loony integrity that has made them vastly more influential, in their way, than comparable works of the supernatural by exquisite stylists such as Edith Wharton or Henry James.