London police detective Maeve Kerrigan has a real dilemma this time around. There is a new serial killer on the loose and he is a bad one. Somehow, he meets women, gains their trust along with entry into their homes, where he kills them in a ritualistic fashion. Maeve is brought into a special investigative task force to try to catch this murderer, which is an honor, but there is a slight problem. Her partner, DCI Josh Derwent, seems to be a top suspect of being The Gentleman Killer. This is supposed to be kept a secret from him but Josh is not a man that will be left out of things. Maeve admits that Josh Derwent is a lot of unflattering things, yet being a murderer is not on that list. When it comes to light that the current murders may have a beginning in Josh's past, Maeve agrees to keep him informed about the investigation.

This may or may not be a great idea although it will most likely solve the murders a lot faster. Maeve and Josh are both risking their careers by going against direct orders from their superior but Maeve just has to do what she feels is right. She just wants to catch this vicious killer before he adds to his body count.

THE STRANGER YOU KNOW starts out with one of the creepiest openings of any book I've read, and it was delicious scary! Things slow down a little after that but not for long. There is one murder after another, which leads to the forming of the special investigation unit.

Maeve Kerrigan is a rather unusual character. She is tireless, stubborn and quite headstrong when she gets something in her head. That is what makes her a great detective as well as somewhat annoying. I had to question some of her decisions as she went along but she always seemed to come out on top.

DCI Josh Derwent is one of the most complicated characters you are likely to meet in a book. He is very full of himself, rather sexist, and fancies himself to be quite macho along with being superior to most women, especially Maeve. She rarely defends herself when he goes a rampage, which is often, and that can become a little irritating. He is a good cop, though, and I suppose that is what is most important. Derwent has few redeeming qualities, so being great at his job is something at least.

I became very engrossed in THE STRANGER YOU KNOW from the very beginning. That should be obvious by the way I was drawn into the personalities of the characters. The investigation was much like peeling the layers of an onion, revealing only a little at a time. It makes for a fascinating story that Jane Casey crafts expertly. At times compelling, nerve-jangling, mesmerizing and outright frightening; THE STRANGER YOU KNOW offers plenty of twists and turns before reaching a mind shattering conclusion.