Darren Shan's adult series, The City, makes his Cirque du Freak books look like bedtime stories! His second - and newest - installment, Hell's Horizon, is terrifying and gory (in the best way possible, of course). Combining elements of fantasy and science fiction with Incan mythology, this book is unlike any I've ever read before. It reminds me, a little, of the works of Philip K. Dick. Check this book out - it will leave you breathless!