I really enjoyed this book. Jack Nightingale is totally likeable and hilarious character. He is a skilled hostage negotiator but that seems to go south for him.  Then he turns to being a private investigator. Soon people around him die with their last message being "you are going to hell Jack Nightingale".  This book is almost impossible to put down and I finished it in just a couple of days. I highly recommend this book. Just enough of the supernatural to make it chilling. Well done!