Thank you to Netgalley for ARC in return for an honest review. Having read into the Darkest Corner by EH previously, I was delighted to be approved for Behind Closed Doors. I didn't realize there was already one before this in the series so I was unfamiliar with Lou and Sam's back stories. This did not detract from my enjoyment of the book however. 15 year old Scarlett vanishes while on holiday in Greece with her family. We are taken through her horrendous journey throughout Europe over a ten year period while also being involved in the dealings of the MIT in the UK at the present team...with a brilliant entertaining of the stories. I never wanted to put this book down...my heart broke for Scarlett and for her sister Juliette left behind. This book was a definite page turner and the brutality of human trafficking and prostitution is laid bare. Twists and turns throughout the book and Scarlett's harrowing narrative chilled me to the core. - no overtly graphic detail was needed to strike a chill into the readers heart Really liked Lou as a character...found her passion and drive for work combined with a developing relationship left us feeling she was a tough cookie with a vulnerability about her that keeps her human. I really couldn't put this book down - am heading straight to Amazon to buy the first one in the series now!