Perdido Street Station/Nightmare Fuel


 * Mayor Rudgutter's audience with the Weaver.
 * Magesta Barbile discovered by a product of her experimentation. The experiments themselves are also (literally) this to the citizens of New Crobuzon after a while.
 * The descriptions of the Cacotopic Stain were terrifying for some readers.
 * The Ambassador of Hell, a demon with two voices, one a carefully calm and level tone and the other a tortured voice screaming in agony.
 * Remaking: Criminals in New Crobuzon can be "Remade", twisted by science and magic to be punished for their crimes. Like having their legs cut off and replaced with tank treads or having their heart replaced with an internal boiler. There is a passage in the story that talks about the Remakers having a "sick sense of art" about the punishments. See Squick.
 * Lin's childhood.
 * Going back and re-reading the scene of Isaac's dreamshit-induced visions, now that you know that.