These two authors really know how to write a suspenseful, dramatic thriller. This novel does not disappoint and their second novel, The Wife Between Us is even better than this one. This is one fast rollercoaster of a ride. You connect with the main character quickly and really wonder where exactly this strange, rich doctor is going to be taking her. Half way through the book you may be able to figure out a little bit of the puzzle and the idea behind the doctor's studies. This part annoyed me a little bit just because I felt like it wasn't justifiably enough. There should be more reason behind the actions of the doctor and the studies. Overall I really enjoyed the book. I would recommend you read this and their other novel.