This is the kind of horror where you fall asleep just fine after reading it, but when you wake up in the middle of the night for no reason you find yourself looking around the room for your own doppelganger and a glass of laudanum. It's creepy, thought provoking, and fascinating because it takes two very real authors (Charles Dickens and Wilkie Collins) and places them at odds with a mesmerising monster named Drood. It's a long book, and the pontificating and endless descriptions of drug use get a little boring, but overall Simmons does a great job of setting the mood and building a haunting story.