The Redbreast by Jo Nesbo
This Norwegian detective story is complex, unusual and hard to put down, the characters are not lovable but are believable and the plot twists and turns to keep you guessing. Every detail is connected by the end of this book, but you get a non-stop intellectual workout keeping track of the ins and outs of the characters, their problems, and their potential enemies, and the conclusion challenges everything you remember as the loose ends are tied up!